Potato, Carrot, and Turnip Gratin

Ingredients

• 1 tablespoon unsalted butter
• 1/2 onion (, sliced thinly (not diced))
• 1/2 cup white wine
• 2 cloves garlic (, minced)
• 2-3 potatoes (, peeled and sliced thinly)
• 2 turnips (, peeled and sliced thinly)
• 3 carrots (, peeled and sliced)
• 1/2 cup heavy cream
• 3/4 cup Parmesan cheese
• 2 tbsp fresh parsley
• 1/4 teaspoon salt
• 1/4 teaspoon ground black pepper