Preheat the oven to 375°F (190°C).
In a skillet, heat olive oil over medium heat.
Season the chicken breasts with garlic powder, onion powder, salt, and pepper.
Brown the chicken in the skillet for about 5 minutes on each side.
In a large bowl, combine cream of chicken soup, chicken broth, and dried thyme.
Add the frozen mixed vegetables to the soup mixture.
Place the browned chicken breasts in a greased casserole dish.
Pour the soup and vegetable mixture over the chicken.
Sprinkle shredded cheddar cheese on top.
Bake for 30-35 minutes or until the chicken is cooked through and the cheese is bubbly.