TexMex Summer Squash Bake

2 pounds summer squash, roughly chopped (about 10 cups)
1 small finely chopped yellow onion
1 4-oz can chopped green chiles
1 4 1/2-oz can chopped jalapenos, drained
1/2 teaspoon salt, or to taste
2 1/4 cups grated extra-sharp Cheddar cheese, divided
1/4 cup whole wheat flour
3/4 cup mild salsa
4 green onions, thinly sliced, for garnish

1. Preheat oven to 400°F. Coat a 9-by-13-inch baking dish with cooking spray.
2. Combine squash, onion, chiles, jalapenos, salt and 3/4 cup cheese in a large bowl. Sprinkle with flour; toss to coat. Spread the mixture in the prepared baking dish and cover with foil.3. Bake the casserole until it is bubbling and the squash is tender, ~35. Spoon salsa over the casserole and sprinkle with the remaining 1 1/2 cups cheese. Bake, uncovered, until golden and heated through, ~ 30 minutes. Sprinkle with green onions.