Lightly grease a small casserole dish.

In a large bowl toss the bread cubes together with 1 tablespoon olive oil and a dash of salt and pepper. Heat a large skillet over medium heat. Add the bread cubes and cook, tossing occasionally, until they are light brown. Remove the pan from the heat. Put half the bread in the casserole dish and the other half in the large mixing bowl. Set aside to cool.

Wipe out the skillet and add the remaining 1 tablespoon olive oil. Heat until shimmering then add the onions. Sauté the onions until translucent, about 5 minutes. Add the garlic, thyme and a dash of salt and pepper. Cook, stirring constantly for about 1 minute or until the garlic is fragrant. Add the spinach and cook until the the spinach is wilted. Remove the pan from the heat.

Sprinkle half the cheeses over the bread cubes in the casserole dish then top with the spinach onion mixture and half the tomatoes. Layer the remaining bread cubes over the spinach, then top with the remaining tomatoes, Gruyere and Parmesan.

In the large mixing bowl, whisk together the eggs, crushed red pepper and the half-and-half. Season with a dash of salt and pepper and gently pour the eggs over the spinach and bread cubes.

Cover the casserole dish with plastic wrap and refrigerate overnight.

Thirty (30) minutes before baking, remove the dish from the refrigerator. Preheat the oven to 350 degrees. Bake until the custard is set, about 45 - 50 minutes or until the top is golden brown.

Cool for 15 minutes before serving.