I was pointed here by a friend who thought I might have some input. By way of voir dire, my credentials are these: I've been an avowed meat eater attached to an avowed non-militant vegetarian for 19+ years. I do all the cooking, and it's a wonderful life. I'll get into some details below, but right up front let me say that learning to cook for our 4-year-old daughter's elevated tastes has probably the bigger challenge, day to day.
So, you enjoy meat, eh? Fine. I don't know you or [redacted], but it sounds like you're both foodies, which should help. Ability to appreciate interesting flavors and textures will give you much more variety to experiment with while you find a groove. As long as [she] is willing to tolerate the presence of meat in your home and on your table, there should be very few issues. I joked above that my wife was "non-militant", but this isn't a given - where you'll be compromising by finding ways to feed the both of you without meat on her plate, her compromise will have to be to let you have your meat without comment, snark, or political lectures. This seems obvious and probably patronizing to two adults, but it has to be stated. In our life together, the only restriction my wife has put on my enjoyment of meat is a prohibition on cooking lamb indoors (stemming from a particularly fragrant preparation of filling for Tiropita).
Your ultimate goal is to find that balance where cooking for the both of you results in a meal that satisfies both without being double the work. Steamed veggies and pasta isn't going to satisfy her every night, just as omitting meat from your shared meals wouldn't satisfy you.
Again, I don't know either of you, so the first question is "What proteins will she eat?" I've got it easier than many people, since my wife is technically Lacto-Ovo-Pescetarian (i.e. Dairy, Eggs, Seafood Ok). To be clear, years of not eating meat has left my wife in a state that the inclusion of meat products is sometimes hard for her to digest - a restaurant that uses chicken stock in a soup plus a clueless or careless waiter will usually equal a night of GI discomfort, at least. Her dietary choice is based on taste and texture, not a political or heath motivation, but there are boundaries I have to respect. My father in law is (relatively recently) strictly vegan for health reasons, and while I can comfortably cook a few meals for him, living with him full time would require further refinement of my thinking and practice. If [she] can/will eat seafood or the like, then a good place to start would be the relatively small step of replacing the meat protein in a meal you're already comfortable cooking. No matter how much you like meat, replacing one piece of beef/pork/poultry a week with a salmon fillet should be tolerable. If not, you've got to learn to cook salmon! For non-fish eaters, you'll be exploring the non-protein substitute realms like portobello mushrooms and soy-substitutes, at least initially. This isn't a "solution", but it's a way to soften the blow and flatten out the learning curve a bit while you adjust to the challenge.
So the real "meat" of the problem, then, is how to construct meals (and a life together) where meat becomes a "side dish". You're free to go through the effort of cooking two completely parallel meals, but I've found my life greatly simplified by adjusting my thinking a bit and building a meal where my meaty protein is the tasty side-dish that some at the table simply don't eat. It's a break from classical thinking, especially in America, but it's right in line with the more humble fare (think rustic/peasant/whatever euphemism makes sense) of people who traditionally couldn't afford big portions of meat. Almost all great "ethnic" meat-containing meals are more meat-heavy Americanized versions of what was originally a poor persons way to stretch a meager supply of meat to feed a family. If you can "think like a peasant", and work on creating satisfying and flavorful meals where meat is the cherished coup de grace, you'll be on the right track.
To that end, I make a lot of meals where the meat is basically "optional". If we use the "classic" meal of a protein, a starch, and a vegetable, as a starting place, then a more veggie-friendly meal would be a dish where perhaps the center of the meal is a starch that contains a veggie and (optimally) a non-meat protein, and you're free to pair it with a meat on the side. You're limited only by your imagination here, but exploring ethnic or traditional foods will point you in the right direction. Anything like Risotto, Pilaf, Pasta, Curries, etc. can be a vehicle for this kind of meal. My usual method is "pilaf". I say method, because I typically don't use just rice - we like everything from cous cous to quinoa or a mixed grain type combo. If you have a Trader Joe's handy, their "Harvest Grains Blend" (Orzo, Pearled cous cous, red quinoa, and split garbanzo beans) is a great example. Sautee your favorite vegetables (mixing hard and soft for texture is a good idea), add the grain mix and sautee briefly, then add your veggie broth and voila'. Toss in some herbage, a little acid, some raw tomatoes or raisins or nuts, grate a hard cheese over the top and that alone should be a hit. Plate that next to 4-6oz of any tasty protein I care to cook, and I'm stuffed.
The real goal is to take pride and care with what most cooks would call a side dish, and you'll find that they can become increasingly significant components of your meal. Revel in the craft of slow-cooking beans or rolling the perfect spring roll. Take pride in getting your mushrooms properly browned.
The same thinking applies to all the components of a meal. Our 4-year-old's favorite meal is "Taco Night". In the old days I prepared the standard condiments (pico de gallo, guacamole, shredded cheese) and some cheap tortillas and separate servings of a soy-based taco filling and a very carefully selected carne- or pollo-asada. The meat was my highlight, I'd drive miles to the tiny little Aztec market for their excellent pre-marinated meats. Over time, I evolved to using really good tortillas and adding some more interesting vegetarian fillings and condiments (black beans with lime, sauteed zucchini, Cotija cheese aka queso-fresco or queso-blanco) and now the only person who actually wants the soy-filling is the 4-year old, because it tastes like "Taco Bell". More importantly, those fillings are so good that I will sometimes omit a meat filling alltogether or the meat will be part of a multi-use preparation (more on this later). The same strategy applies to dozens of meal types - start fretting over really nailing the non-meat aspects of a dish, and your vegetarian should be well satisfied by eating whatever you're eating, minus that one ingredient.
Another meat-eaters strategy that dovetails nicely with the "think like a peasant" ethos is to figure out how to stretch meat preparations into multiple meals. Beyond the actual cost issue (and learning to do this has definitely cut my food costs), there's the savings in labor. By all means, make that Spanish style beef stew you linked, but figure out what else you can do with it. To my way of thinking, that preparation would be incredible on day 2 or 3 as the filling for a taco, or ladled over a slice of crusty bread and topped with cheese and toasted in the oven. Spend the time and energy on making as big a batch as you can consume before it goes "bad" and reap the reward for days.
My most basic example of multi-use of meat is the whole rotisserie chicken. Factoring in that the only carnivores are myself and a 4-year-old, a single chicken is at LEAST three meals. We do things a bit differently than many people, because my daughter is awesome and prefers dark meat poultry if eating it "straight". So day 1 is chicken thighs next to either rice and a veggie or the fortified pilaf I mentioned above. Day 2 would be the breasts either shredded as filling for enchiladas (made right after I finished making cheese/onion enchiladas for the wife), or seasoned and lightly re-fried for taco filling. The remainder (wings & bits) would be enough for inclusion in a weekend breakfast hash. This is all obvious stuff, but the point is that using a previously-prepared meat allowed me to focus my cooking time on quality vegetarian-friendly components to 2 or 3 meals, then add the meat in with minimal prep.
So far, this has been a lot of "philosophy", but I do have one "trick": Find her "trigger" foods. There are a few ingredients that my wife simply loves. I noticed early on in our relationship that listing ingredients like "pear", "polenta", or "peas" on a menu virtually guaranteed she'd order that dish. This is one of my "outs". On a night when I need to punt and can't figure out how to build a veggie-compatible meal, I fall back to a trigger food, and it's guaranteed to satisfy. A quick pre-bagged salad tossed with some julienned pear or some pre-made polenta fried in butter and topped with sauteed mushrooms and grated cheese is the near-zero effort way to make sure the wife is happy no matter what else I've served.
My last tip is to occasionally just revel in the meat. There is nothing that excites our 4-year-old quite as much as seeing the beer cooler on the counter, 'cause that usually means dad's going to be doing a steak en sous vide. I've shamelessly pimped her out and had her make friends with the meat cutter at my local market - and now he will happily cut a 2" ribeye right off a fresh primal for her, every time she asks him to. That Flintstone-sized slab of steak makes the wife roll her eyes every time, but us carnivores love it, and there's always leftovers for whatever meal we can think up next. On days when I'm having that giant steak to celebrate something, I find it supremely convenient that lobster sous vides at the same bath temperature as steak, so it goes in the water when the steak comes out for searing. If it's just a night where I'm craving beef, then I make sure to have either one of the aforementioned "trigger foods" or something at least hearty (see fortified pilaf, above) .
In the end, if your'e successful, food will unite you, not separate you. It's going to be a process, but the more you can work together on figuring out what she will/won't eat and what foods or preparations will satisfy her, the more happier you both will be.