Preheat the oven to 350 degrees F (175 degrees C).
Pour crushed tomatoes into the bottom of a casserole dish. Layer 1/3 of the rice, 1/3 of the beans, 1/3 of the diced tomatoes, 1/3 of the seitan, 1/3 of the vegan cheese, 1/3 of the tortillas, and 1/3 of the enchilada sauce into the dish, in that order. Repeat with 2 more layers.
Bake in the preheated oven until vegan cheese melts and casserole is heated through, about 45 minutes.