How long do you cook a 3lb chuck roast medium rare on a gas grill?

I wouldn't recommend cooking a chuck roast medium rare or on a gas grill. Chuck roast is a very tough cut and must be cooked "low and slow" for it to get tender. I always make pot roast out of mine. Season on both sides and dredge in a little flour. Brown in hot oil and cover with beef broth which has been seasoned well with sliced onions and garlic. Add a bay leaf (or not) and a shot of Worcestershire sauce. I cook mine in a pressure cooker for 35 min or over low heat for a couple hours til tender. Add vegetable during last half hour.

Chuck Roast Grill

The roast needs to cook 10 to 15 minutes, 5 to 7 on each side, and then needs to sit for 3 minutes.

SOUTHERN COMFORT GRILLED CHUCK ROAST

2 1/2 to 3 lb. chuck roast

1/4 c. Southern Comfort bourbon

1/2 c. soy sauce

1 1/2 c. water

1/3 c. brown sugar

1 tsp. lemon juice

Place roast in deep dish. Combine all other ingredients together for a marinade. Pour mixture over roast. Put roast in refrigerator and marinate for 5-6 hours. Turn roast every 30 minutes. Cook on grill over charcoal (or on high for gas grill) for 30-60 minutes, depending how well done you like it.

Oven Method: 400 degrees for about 40 minutes. Slice thin and serve.

GRILLED CHUCK ROAST

3-4 lbs. chuck roast

1 clove garlic

1 tbsp. brown sugar

1/2 tsp. ginger

1/2 tsp. pepper

1 tbsp. oil

2 tbsp. water

1/2 tsp. Accent

1/4 c. soy sauce

Meat tenderizer

Three hours before serving, sprinkle with meat tenderizer, 1/2 teaspoon per pound. Pierce with fork. Mash garlic with sugar to fine pulp. Mix all other ingredients in shallow dish large enough for cubed meat (1 1/2 inch cubes). Marinate 1 1/2 to 2 hours. Do not salt. Grill for 10 minutes.

http://www.cooks.com/rec/view/0,1727,153190-244195...

http://www.cooks.com/rec/view/0,1727,157187-243194...

http://www.certifiedangusbeef.com/