Portobello Mushroom Bolognese Sauce

Ingredients (11)

• + 1 onion, quartered add to pantry
• + 1 large stalk celery, halved add to pantry
• + 1 carrot, quartered add to pantry
• + 4 large portobello mushrooms, stemmed add to pantry
• ✓ 1 tablespoon vegetable oil, or to taste
• ✓ salt to taste
• + ½ cup white wine add to pantry
• + ¼ cup milk add to pantry
• + ¼ teaspoon ground nutmeg add to pantry
• + 2 (15 ounce) cans whole tomatoes, or more to taste add to pantry
• + ½ cup water add to pantry