Root Beer Crock Pot Roast

4 lbs eye of round or chuck roast
1 1/2 tsp salt, divided
1 tsp pepper, divided
1 tbsp vegetable oil
1 large onion, thinly sliced
12oz root beer
12oz chili sauce
1 garlice clove, minced

Sprinkle roast evenly with 1 tsp salt and 1/2 tsp pepper.  Brown roast on all sides in hot oil in large dutch oven over medium high heat.  Add onion and cook until golden.  Place browned roast in slow cooker.  In a mixing bowl, stir together remaining salt and pepper, root beer, chili sauce and garlic.  Pour mixture over roast in slow cooker.  Cook on low 6-8 hours.