Cut the zucchini, squash, and large onion into 1 inch pieces. Spread evenly on a lined baking sheet. Drizzle with olive oil, and sprinkle with salt and pepper. Bake at 350°F for 30 minutes.

Meanwhile, place the green chiles, sour cream, vegetable stock, cumin, lime juice, garlic salt, and cilantro in a blender and pulse until smooth. Set aside.

Prep the corn salsa: dice the tomatoes and onions and toss together in a large bowl. Add the corn, cilantro (1-2 tbsp according to taste, start with 1 tbsp), lime juice, cumin, and a dash of salt and pepper. Mix well and set aside.

Remove vegetables from the oven (leave the oven on). Evenly fill each tortilla with the vegetables and a tablespoon of shredded cheese. Roll and place seam down, tightly side by side, in a 9x13 baking dish.

Pour and spread the green chile sauce over top, and sprinkle the cheese over the enchiladas. Bake at 350°F for 10 minutes, or until cheese is melted and bubbly. Serve with corn salsa.