01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - Roll puff pastry onto prepared baking sheet. Fold edges inward to create a 1-inch border. Prick base with fork.
03 - Bake pastry for 10 minutes until lightly golden. Remove from oven and press down any puffed areas.
04 - Whisk together eggs, milk, cream, Dijon mustard, salt, pepper, and smoked paprika until completely smooth.
05 - Distribute cooked bacon (or mushrooms), spinach, tomatoes, and spring onions evenly over pastry base. Sprinkle cheddar cheese on top.
06 - Pour egg mixture gently over fillings, spreading evenly. Return to oven and bake for 25 minutes until center is set and top is golden brown.
07 - Cool for 5-10 minutes. Garnish with chopped chives, slice into portions, and serve warm.