Mahi Mahi with Onions and Mushrooms

INGREDIENTS

• 2 tablespoons olive oil
• 3 small onions, chopped
• 4 cloves garlic, minced
• 5 button mushrooms, sliced
• 1 1/2 pounds mahi mahi
• salt and pepper to taste
• 1/4 cup white cooking wine
• 1 tablespoon fresh lemon juice
• 1 teaspoon cornstarch
• 2 tablespoons water