For a richer flavor, use whole milk or half-and-half instead of skim milk. Feel free to experiment with different cheeses, such as Gruyere, Parmesan, or provolone. Add other vegetables like mushrooms, bell peppers, or sun-dried tomatoes for extra flavor and nutrients. If you don't have herbes de Provence, use a blend of dried thyme, rosemary, and savory. To prevent the top from browning too quickly, tent the strata with foil during the last 15-20 minutes of baking. This strata can be served warm or at room temperature.