Curried Coconut Beef with Winter Vegetables

1 tablespoon vegetable oil

2 pounds beef stew meat

1 large onion, chopped (1 cup)

2 cloves garlic, finely chopped

1 1/2 tablespoons curry powder

1 tablespoon packed brown sugar

2 tablespoons lemon juice

3 medium carrots, chopped (1 1/2 cups)

2 medium parsnips, peeled and chopped (1 cup)

1 1/2 cups chopped peeled sweet potatoes

1 teaspoon salt

1/4 teaspoon pepper

Chopped fresh cilantro, if desired