Beef and Onion Stew (Stifado)

1 medium onion, chopped
2 cloves garlic, minced
3 tablespoons olive oil
1 (2 pound) boneless beef chuck, tip or round, cut into 1-inch cubes
1/2 cup dry red wine
2 tablespoons red wine vinegar
1/2 teaspoon salt
1/4 teaspoon coarsely-ground pepper
1 bay leaf
1 stick cinnamon
1 (8 ounce) can tomato sauce
1 1/2 pound pearl onions, peeled
Crumbled feta cheese

Cook and stir chopped onion and garlic in oil in Dutch oven over medium heat until onion is tender; remove with slotted spoon. Cook beef in remaining oil, stirring frequently, until all liquid is evaporated and beef is brown on all sides, about 25 minutes; drain fat. Return onion and garlic to Dutch oven. Stir in remaining ingredients except onions and cheese. Heat to boiling; reduce heat. Cover and simmer 1 hour and 15 minutes.

Add white onions. Cover and simmer until beef and white onions are tender, about 30 minutes. Remove bay leaf and cinnamon. Garnish with cheese.