Meat Loaf with Sauteed Mushrooms

Name: Meat Loaf with Sauteed Mushrooms
Ingredients: 5 tablespoons olive oil; 3 large onions, coarsely chopped; 1 tablespoon sugar; 2 teaspoons dried oregano; 2 garlic cloves, minced; 1/4 cup apple cider vinegar; 1 pound lean ground beef; 1 pound ground pork; 1 14 1/2-ounce can crushed tomatoes with added puree; 2 large eggs; 1 cup crushed saltine cracker crumbs; 1/2 cup chopped celery leaves; 1/4 cup dry white wine; 1 1/2 teaspoons salt; 3/4 teaspoon ground black pepper; 1 pound mushrooms, sliced