Bypassing the meat counter saves you money and adds new life to a Tex-Mex classic. Best of all, your family won't miss the steak. Spicy poblano chiles add meaty texture and cut the richness of the cheese.
Preheat oven to 275 degrees. Wrap tortillas in parchment-lined foil and warm in oven, 15 minutes. In a small pot, heat beans over low.
In a large skillet, heat oil over medium-high. Add onion and chiles and cook until softened, 12 to 15 minutes. Add zucchini and cook until crisp-tender, 6 minutes. Add corn and cook until warmed through, 3 minutes; season with salt and pepper. Spread beans on tortillas and top with vegetables; serve with salsa, sour cream, cheese, and lime wedges.
Shopping Tip If you like your Tex-Mex with extra heat, look for spicy refried beans--they often include some kind of chile.