Preheat your oven to 375°F (190°C).
In a large bowl, whisk together eggs and heavy cream until well combined.
Add salt and pepper to taste.
Stir in the shredded cheese and diced vegetables.
If using, add the diced meat to the mixture.
Place the pastry shells on a baking sheet.
Pour the egg mixture into each pastry shell, filling them about ¾ full.
Bake in the preheated oven for 20-25 minutes, or until the filling is set and the tops are golden.
Remove from the oven and allow to cool slightly.
Garnish with fresh herbs if desired, then serve warm.