Preheat oven to 350°F.

Place tilapia in a baking pan. Place the vegetables over the top of each piece of fish.

In a small bowl, whisk together olive oil, water, lemon juice, garlic, cumin, and cayenne pepper. Pour the mixture over the vegetables. Let the fish marinate for at least 15 minutes. Bake covered for 10 minutes. Uncover and bake an additional 15 minutes.