I'm very new to the cooking world, so forgive me if this is a stupid question. My wife makes a great beef stew with a tomato-based sauce. When she puts it in a slow-cooker, she doesn't pre-cook the meat, it just cooks right in there. If I were to add lamb along with the beef, could I expect it to cook in about the same manner, or should it be browned first? Any other possible issues or compelling reasons not to add lamb? Any advice is appreciated.