Spicy Beef Chili

1 tablespoon oil
1 pound beef sirloin, cut into 1 inch pieces
1 cup chopped onions
1 medium green bell pepper, seeded, chopped
2 garlic cloves, crushed
2 28 ounce cans Italian plum tomatoes, undrained, cut up
2 to 3 chipotle chiles, cut up
1 teaspoon salt
1 teaspoon liquid smoke
1/2 teaspoon pepper

Topping:
1 avocado, peeled, pitted and chopped
1 teaspoon lime juice
1/2 cup sour cream

Heat oil in large sauce pan or dutch oven over medium high heat until hot. Add beef, cook 8 to 10 minutes or until beef is well browned. Stir in onions, bell pepper and garlic cook 4 to 5 minutes or until vegetables are crisp tender.