Mushroom Glazed Pork Chops

Name: Mushroom Glazed Pork Chops
Ingredients: 10 ounce(s) cremini mushrooms, trimmed and quartered; 8 ounce(s) fresh shiitake mushrooms, stems discarded, cut into 1-inch pieces if large; 2 clove(s) garlic, very thinly sliced; 1 teaspoon(s) sugar; 1 tablespoon(s) sherry vinegar; 1 teaspoon(s) sherry vinegar; Salt and pepper; 1 tablespoon(s) vegetable oil; 4 (each 6 ounces, 1-inch thick) boneless, center-cut pork loin chops; 1 medium (6- to 8-ounce) onion, finely chopped; 1/4 cup(s) cognac; 1/4 cup(s) light cream; 2 fresh sage leaves, thinly sliced