Yes! If your slow cooker has the sauté function, sauté the turkey, mirepoix, and garlic as directed. Then add the lentils, tomato, and stock and cook on high for 3-4 hours or low for 6-8 hours. If your slow cooker doesn't have the sauté function, I'd recommend sautéing the ingredients on the stovetop then transferring to the slow cooker.