Zucchini and Tomato Frittata

Preheat oven to 425 degrees. In a 10-inch nonstick skillet over medium heat, warm oil. Add onion, zucchini, and thyme; cook, covered, stirring often, until tender but not browned, 8 to 10 minutes. Uncover, and cook until all the liquid in the pan evaporates. Season with salt and pepper; remove skillet from heat.

In a medium bowl, whisk eggs, milk, and cheese, salt, and pepper. Pour egg mixture over zucchini, gently lifting zucchini to allow eggs to coat bottom of pan. Arrange tomatoes in an overlapping pattern on top.

Return skillet to medium-low heat, and cook until sides are set yet still slightly runny on top, 15 to 20 minutes. Place in oven, and cook until the center is cooked through when tested with a wooden skewer, and the tomatoes are browned, 10 to 15 minutes. Remove from oven; gently slide a heatproof spatula around the edges and underneath to loosen from skillet. Serve immediately.