Easy Slow Cooker Pot Roast

1/4 c. water; 1 med. onion; 5 potatoes, cut in quarters; 1 envelope onion soup mix; 1/4 tsp. each salt, pepper, and dried thyme; pot roast meat. Place water and and vegetables in slow cooker, sprinkle onion mix on vegetables. Stir. Rub salt, pepper and thyme all over pot roast (I feel that putting it in semi-frozen helps with moistness.) Cook with lid in slow cooker low 8-9 hours or high 5-6 hours til tender.