In a large skillet, heat the olive oil over medium heat. Add the diced sweet onion and minced garlic, and sauté until they become translucent and fragrant, about 3–4 minutes. Remove from heat.
In a mixing bowl, combine the cream of chicken soup, cream of mushroom soup, sour cream, onion powder, garlic powder, dried parsley flakes, and dried dill. Mix until well combined.
Next, stir in the shredded chicken, mixed vegetables, crumbled bacon (reserve a few tablespoons to sprinkle on top of the casserole), and 2 cups of shredded cheese.