Hot Stuffed Grape Leaves with Lamb

Name: Hot Stuffed Grape Leaves with Lamb
Ingredients: 1 jar preserved grape leaves, drained; 1/2 cup long-grain rice; 1/4 cup plus 2 tablespoons olive oil; 1 onion, finely chopped; 3 cloves garlic, minced; 1/2 pound lean ground lamb; 1 teaspoon dried oregano; Salt and freshly ground black pepper; 4 ounces feta cheese, crumbled finely or grated; 3 tablespoons finely chopped parsley; 2 tablespoons finely chopped mint; 1 teaspoon sugar; Juice of 1 lemon; 1 lemon sliced, for garnish; Mint leaves, for garnish