01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - Unroll the puff pastry onto the prepared baking sheet. Score a 1-inch border around the edges with a sharp knife, without cutting all the way through. Prick the center area with a fork.
03 - Bake the pastry for 10 minutes, until slightly puffed and pale golden. Remove from oven and gently press down the center if it has risen.
04 - In a medium bowl, whisk together eggs, heavy cream, salt, pepper, and smoked paprika if using.
05 - Sprinkle the grated cheddar evenly over the center of the pastry, staying within the scored border. Pour the egg mixture over the cheese. Top with chopped bacon, halved cherry tomatoes, spinach, and green onions.
06 - Return the tart to the oven and bake for 20-25 minutes, or until the eggs are just set and the pastry is golden brown.
07 - Remove from oven and let cool for 5 minutes. Garnish with fresh chives. Slice and serve warm.