These treats can be prepped and frozen for up to 3 months, so make a double batch for an easy future side.
- 2 tsp. olive oil
- 2 tbsp. finely chopped red onions
- 1 1/2 c. packed baby spinach coarsely chopped
- 2 tbsp. grated Parmesan cheese
- 1 tsp. grated lemon zest
- 1/2 sheet frozen puff pastry thawed
- 1 egg beaten
Heat oven to 400°F. Heat oil in large nonstick skillet over medium heat. Add onions; cook 5 min. or until tender, stirring. Add spinach and 1/8 tsp. salt; cover and cook 3−5 min. or until spinach is wilted, stirring. Remove from heat; stir in cheese and zest. Cool.
On floured surface, roll out pastry. Spread with spinach mixture, leaving 1/4" border around edges. Brush top of short side with water; starting from bottom of short side, roll up pastry jellyroll style. Turn so seam side is down and brush top with egg. Cut into 10 (1/2"-thick) slices. Arrange slices on greased baking sheet; brush with more egg. Bake 12–15 min. or until puffed and golden brown.