Potato & Spinach Gratin

Ingredients

• 1/4 (62 ml) butter
• 1 onion, finely chopped
• 2 garlic cloves, finely chopped
• 1/4 (62 ml) flour
• 3 cups (750 ml) milk
• 1/4 tbsp. (1ml) nutmeg
• 6 medium potatoes
• 3 cups (750ml) fresh spinach
• 2 cups (500ml) of grated mozzarella cheese
• Salt and pepper to taste