01 - Preheat the oven to 400°F. Line a baking sheet with parchment paper.
02 - Roll out the puff pastry onto the prepared sheet, folding the edges inward to create a 1-inch border. Prick the base thoroughly with a fork.
03 - Bake the pastry for 10 minutes until lightly golden. Remove from the oven and gently press down any puffed areas to create an even base.
04 - In a large bowl, whisk together eggs, milk, cream, Dijon mustard, salt, pepper, and smoked paprika until completely smooth and well combined.
05 - Distribute cooked bacon, spinach, tomatoes, and spring onions evenly across the pre-baked pastry base. Sprinkle cheddar cheese uniformly over the vegetables.
06 - Pour the egg mixture gently over the fillings, ensuring even distribution. Return to the oven and bake for 25 minutes until the center is just set and the top is golden brown.
07 - Allow the tart to cool for 5–10 minutes before slicing. Garnish with chopped fresh chives and serve warm.