Pastas and tacos... that's like, 5 of the 4 basic food groups round here!
For pastas, I like to throw in some frozen veggies. There's a couple of blends that I really like - one has asparagus in it, the other one is a stir-fry blend I think (water chestnuts, baby corn and the like). If you're not into blends, individual frozen veggies work, too. Spinach, cauliflower, broccoli - all delicious in pasta. You can either boil them up with the pasta or throw them in with the sauce while its heating. It's good both ways. For sauce, there's a few Hunts (US) varieties that are vegan and I think other brands are, too, but I'm not sure of that (I usually make my own sauce). I've also thrown beans in at times (it's really good with pasta) and topped my spaghetti, farfalle, etc with ground nuts instead of a vegan parm. Yummay!
For a change-up, I like to make rice or another whole grain and throw in whatever veggies suit my fancy along with whatever beans I'm in the mood for. Top with ground nuts or sliced avocado and dig in. OR you can take that veggies/beans combo and pile it on a baked potato. Top with a nutritional yeast sauce or a good bean dip, slightly thinned.
For tacos, I like no-fat refried beans. The ingredients are usually more simple (beans, water, salt) than other varieties. I doctor them up with a bit of minced garlic and a few splashes of El Pato or a favorite chunky salsa and heat them slowly. For the add-ons, shreadded cabbage, finely chopped kale, diced tomato, diced avocado, sliced Mexican squash or just about anything would be good. I've even taken frozen veggie blends, heated them up a bit, chopped them finely and put them in my tacos. If you like fake meats, they're pretty good in a taco too but some fakies are better than others to be warned.
And don't forget that whatever is good in a taco will absolutely rock as a tostada, too.
Just sub out the folded shell for a flat one and treat it like a pizza.
I've also just recently gotten into raw foods which is pretty nice because that stuff isn't cooked at all - just whirred in a processor and piled on to something else. Handy.
As you can see, my approach isn't learning a bunch of recipes; it's learning how to make a few things then changing up those ingredients to make it seem like it's something completely different.