Thaw puff pastry overnight in the refrigerator or for about 30 minutes at room temperature. Preheat oven to 400°F (200°C) and lightly grease ramekins with cooking spray or butter.

Roll out thawed puff pastry to about 1/8 inch thick. Cut circles large enough to fit the ramekins, pressing each circle into the greased ramekins to form shells.

Line each pastry shell with parchment and fill with pie weights or dried beans. Bake for 12–15 minutes until edges are golden brown; then remove weights and continue baking for 3–5 minutes.

Heat olive oil in a skillet over medium heat. Sauté shallot and garlic for 2–3 minutes until fragrant. Add spinach and stir until wilted, around 2 minutes. Mix in cream cheese, heavy cream, Parmesan cheese, and nutmeg.

Spoon the spinach filling into each pastry shell. Crack a large egg on top of the spinach in each shell, season with salt and pepper.

Brush exposed pastry edges with egg wash. Return ramekins to the oven and bake for 12–18 minutes, depending on desired yolk consistency.

Once baked, garnish with chopped chives. Serve hot in ramekins or slide onto plates.