Auntie Di's Alfredo Sauce

Ingredients

• 2 cups half and half
• 1 tbsp butter
• 1 tsp garlic, crushed
• 1/2 cup grated parmesan
• 1/2 cup grated romano
• 4 large egg yolks
• 1/2 tsp salt
• 1/2 tsp pepper
• 1 pinch cayenne (optional)