Place sliced zucchini, in batches, in a medium hot pan with olive oil and season with southwest seasoning, or to preference. Zucchini can be fried before or during assembly of the casserole, I prefer during.
Spoon 4 Tbls Green Enchilada sauce in a casserole dish and cover with 2-3 corn tortillas.
Place 1/3 of pinto beans on top and season with cumin, pepper and smoked paprika. Add first batch of fried zucchini on top of beans. Then add 1/3 of the Pico de Gallo or salsa. Spanish rice can also be added as an additional layer. Top layer with another 2-3 corn tortillas and repeat layers starting with the green Enchilada sauce.
Turn oven to 375 while you add the last layer of corn tortillas. You can make 2 or3 layers, depending on the size of your casserole dish. Spoon more Enchilada sauce on the corn tortillas, then spread sour cream on top. Sprinkle shredded cheese generously over the entire dish. Place in preheated oven and let bake through for 20 minutes until it is bubbly and cheese is slightly browned.