Return the pan with the reserved bacon fat to medium heat. Add the chopped spinach and sauté for 1 to 2 minutes, just until wilted. Lay on paper towel to dry.

Roll puff pastry slightly to smooth creases and cut into squares. Press each square into a pan or ramekin, fitting into the bottom and up the sides with a little overhang. Chill while making the filling.

In a small saucepan, melt the butter over medium heat. Whisk in the flour and cook for about 1 minute until lightly foamy but not browned.

Slowly whisk in the milk. Cook, whisking constantly, until thickened enough to coat the back of a spoon, about 2 to 3 minutes. Remove from heat and melt in the cream cheese. Let cool for about 3 minutes.

In a large bowl, whisk the eggs with salt, pepper, and nutmeg. Slowly whisk in the warm bechamel.

Stir in the shredded cheese, sautéed spinach, and chopped bacon.

Divide filling evenly among pastry lined pans or ramekins, filling about ¾ full.

Lay one reserved half slice of bacon across the top of each souffle. Fold any excess pastry lightly across the top of the egg mixture.

Bake for 23 to 28 minutes, until pastry is deeply golden, centers are set but still have a slight jiggle, and the bacon on top is lightly crisped.

Let rest 5 to 10 minutes before serving. The custard will finish setting and become beautifully creamy. Serve in the pan or ramekin or transfer to a plate and serve.