Roasted Tomato and Caramelized Onion Clafoutis

Name: Roasted Tomato and Caramelized Onion Clafoutis
Ingredients: 2 sweet onions, sliced thinly; 1 tablespoon butter or olive oil; 1 1/2 cup cherry tomatoes; 1 tablespoon olive oil; 2 garlic cloves, crushed; 3 tablespoon fresh thyme leaves; 1 teaspoon sugar; 1 teaspoon salt; 1/2 teaspoon white pepper; 4 eggs; 1/2 cup heavy cream; 3/4 cup milk; 2 tablespoon sour cream; 1/2 cup parmesan cheese, finely grated; 1/4 cup flour; 1/2 teaspoon baking powder; 2 teaspoon salt; 1 teaspoon white pepper; 1/2 bunch fresh basil, finely chopped; 1/2 cup gruyere cheese, grated