For bread crumb topping: In a small bowl, toss together bread crumbs, oil, and salt. Place on a small baking sheet.
Bake until lightly browned, about 4 minutes.
For filling: In a 10-inch cast-iron skillet, cook bacon over medium heat until crisp. Remove bacon, and let drain on paper towels, reserving drippings in pan.
In a large saucepan, bring 2 cups water, broth, zucchini, squash, peas, corn, and onion to a boil over medium-high heat. Reduce heat to low, and simmer for 5 minutes. Drain squash mixture, and set aside. Wipe saucepan clean.
Place flour, salt, and garlic powder in saucepan; whisk in cream and milk. Bring to a simmer over medium heat, whisking constantly. Reduce heat; simmer, whisking constantly, until slightly thickened, about 3 minutes. Remove from heat.
Stir squash mixture and chiles into bacon drippings in skillet. Stir in cream sauce. Drop goat cheese by teaspoonfuls over corn mixture.
Bake until bubbly, about 20 minutes. Crumble bacon. Sprinkle bread crumbs and bacon over gratin. Bake 5 minutes more. Let stand for at least 10 minutes before serving.
Recipe by Taste of the South at https://tasteofthesouthmagazine.com/lady-pea-corn-squash-gratin/