The decision of whether to leave the lid on or off when cooking a stew slowly in an oven depends on the desired outcome and the specific recipe you are following. Both methods have their advantages and will result in slightly different outcomes.
Lid on: Cooking the stew with the lid on helps trap moisture and heat inside the pot. This creates a more controlled cooking environment, ensuring that the stew remains moist and tender. It also helps retain flavors and nutrients since less steam and liquid will escape during the cooking process. If you want a tender, moist, and evenly cooked stew, leaving the lid on is generally recommended.
Lid off: Cooking the stew with the lid off allows more evaporation and can result in a thicker sauce or broth. If you desire a thicker consistency or want to intensify the flavors by reducing the liquid content, cooking with the lid off might be a better option. However, this method can lead to some loss of moisture and may require more attention to prevent the stew from drying out or burning.
Ultimately, the choice of leaving the lid on or off will depend on your preferences and the specific recipe instructions. If a recipe calls for a specific method, it's usually best to follow it. However, if there are no specific instructions, you can experiment with both methods to see which one yields the results you prefer. Just remember to adjust the cooking time and keep an eye on the stew to avoid overcooking or drying it out if you decide to cook with the lid off.