7 pounds beef oxtails
1 pound onions, minced
1 ounce salt
1 ounce sugar
1/2-ounce garlic powder
1/4 cup ketchup
1/3 cup soy sauce
2 teaspoons liquid browning or soy sauce
1 teaspoon ground allspice
2 tomatoes, diced
1 bunch scallions, minced
2 cans butter beans, drained
Cornstarch mixed with a little cold water, if necessary