Chicken and Brisket Brunswick Stew

2 large onions, chopped
2 garlic cloves, minced
1 Tablespoon vegetable oil
1 1/2 Tablespoon jarred beef soup base
2 Pound skinned and boned chicken breasts
1 (28-oz.) can fire-roasted crushed tomatoes
1 (12-oz.) package frozen white shoepeg or whole kernel corn
1 (10-oz.) package frozen cream-style corn, thawed
1 (9-oz.) package frozen baby lima beans
1 (12-oz.) bottle chili sauce
1 Tablespoon brown sugar
1 Tablespoon yellow mustard
1 Tablespoon Worcestershire sauce
1/2 Teaspoon coarsely ground pepper
1 Pound chopped barbecued beef brisket (without sauce)
1 Tablespoon fresh lemon juice
Hot sauce (optional)

Sauté onions and garlic in hot oil in a 7.5-qt.
Dutch oven over medium-high heat 3 to 5 minutes or until tender.
Stir together beef soup base and 2 cups water, and add to Dutch oven.
Stir in chicken and next 9 ingredients. bring to a boil.
Cover, reduce heat to low, and cook, stirring occasionally, 2 hours.
Uncover and shred chicken into large pieces using 2 forks.
stir in brisket and lemon juice. Cover and cook 10 minutes.
serve with hot sauce, if desired.