Place a nice lean roast into crockpot on top of cut up carrots, onion and 1/2cup water.  Sprinkle with 1/2 teaspoon Thyme.  Set on low and cook 8 hours.  Remove roast and vegetables, and place in covered casserole to keep hot.
Turn crockpot on high and place lid on.  Mix 4 Tbsp. gluten-free cornstarch with cold water.  Add cornstarch mixture and stir well. Place top back on and continue to cook the gravy until thickened.  Add salt and pepper to taste.  Serve with gravy and vegetables.