Add stew meat, onions and mushrooms to slow cooker.
Sprinkle over the thyme, oregano and pepper.
In a small bowl whisk together the water (only 1.5 cups, not what the packages say) and gravy mixes. Pour over the meat and veggies in the slow cooker.
Cook on low for 8 hours or HIGH for 4 hours without opening the lid during the cooking time.