Barbecued Chuck Roast #2

Barbecued Chuck Roast

3 to 4 pound Chuck roast, 2−½ to 3 inches thick
3 Cloves garlic, minced, crushed or put through a press
¼ cup Red wine vinegar
¼ cup Olive oil
1/3 cup Sherry (just regular, dry sherry − not "cooking" sherry)
1 Tablespoon Soy sauce
1 Teaspoon Dry mustard
Freshly ground black pepper (several healthy grinds)
2 Tablespoons Tomato Ketchup

Mix all marinade ingredients except the Ketchup. Pour over the roast (the
one−gallon plastic zip−lock freezer bags are perfect for this) and marinate
for at least 24 hours. When your grill is ready, remove the roast from the
marinade (reserve the marinade!) and put it on the grill, 4 to 5 inches from
medium coals. Put the cover on the grill. Mix the catsup into the marinade,
and baste 4 or 5 times during grilling. It will take about 1 hour and 15
minutes for the roast to reach 160 degrees (medium). An instant−read meat
thermometer is a handy thing to have for this.