Base Custard:

• 2 tbsp unsalted butter (softened)
• 2 tbsp finely grated Parmesan cheese
• 2 cups half-and-half
• 2 large eggs
• 2 large egg yolks
• ½ tsp kosher salt
• Freshly ground black pepper (to taste)
• Freshly grated nutmeg (to taste)
• Pinch of cayenne or paprika

Filling:

• 2 to 3 cups prepared vegetables (leeks, broccoli, onions, mushrooms, spinach, etc.)
• 4 oz grated or crumbled cheese (Cheddar, goat cheese, Gruyere, etc.)
• 1 to 4 tbsp minced herbs (parsley, chives, tarragon, etc.)
• ¾ cup chopped crisp bacon (diced ham, or salami (optional))

Optional Additive:

• 1 tbsp all-purpose flour (for extra structure, optional)