Food & Cooking Recipes Breakfast & Brunch Recipes Tomato-Onion Casserole 3.7 (53) 3 Reviews By Martha Stewart Test Kitchen Martha Stewart Test Kitchen The recipes developed by our test kitchen team have undergone a rigorous process of development and testing, ensuring that every element is optimal, from ingredient amounts to method and cooking time. This process includes triple-testing recipes to ensure they meet our high standards. The many stellar cooks and food editors who have been part of our team include Sarah Carey, Lucinda Scala Quinn, Jennifer Aaronson, Shira Bocar, Anna Kovel, Greg Lofts, Riley Wofford, Lauren Tyrell, and Lindsay Leopold. Editorial Guidelines Updated on January 22, 2018 Print Rate It Share Share Tweet Pin Email Photo: Con Poulos Prep Time: 10 mins Total Time: 55 mins Servings: 8 If you're a fan the juicy flavor of roasted tomatoes, this easy brunch dish is for you. Ingredients 4 large tomatoes (about 2 pounds), cut crosswise into ½-inch slices 1 large or 2 medium red onions (about 1 pound), cut crosswise into ¼-inch rounds 2 tablespoons extra-virgin olive oil Coarse salt and ground pepper Directions Preheat oven to 450 degrees. In a 9-by-13-inch baking dish, arrange tomatoes and onions in rows, overlapping slightly. Drizzle with oil and season with salt and pepper. Bake until tomatoes are lightly browned and onions are tender, about 45 minutes. Serve warm or at room temperature. Rate it Print