Gather and prep all of the tomato-caramelized onion chutney ingredients to have ready and organized for use.
Place a large non-stick skillet over medium-high heat, and drizzle in about 4 tablespoons of oil. Once hot, add the sliced onion, and allow it to caramelize, stirring frequently, for about 12-14 minutes.
Stir in the garlic, plus a pinch or two of salt and pepper, and the sugar. Once aromatic, add in the balsamic vinegar and stir, allowing it to become syrupy and reduced for about 30 seconds.
Add in the crushed tomatoes, along with the chopped parsley, and stir to combine. Add more salt and pepper to taste, and allow to simmer gently for about 1 minute to meld the flavors.
Set aside and keep warm until ready to serve.
Gather and prep all of the spinach puff pastry ingredients according to the ingredient list above.
Add all filling ingredients to a bowl and mix well to combine. Set aside.
Place a thawed puff pastry sheet on a lightly floured surface, unfold, and gently roll out to make it even and slightly thinner. Cut into 16 small rectangles/squares.
Add about ½ to 1 teaspoon of the filling into the center of each, brush the top edges with egg wash, then fold and press to seal. Repeat until all are done and place on baking sheets lined with parchment paper.
Repeat with the other puff pastry sheet.
Before baking, brush the tops with more egg wash, and chill in the fridge for about 15-20 minutes.
Preheat oven to 400°. Bake the puffs for 20-22 minutes until golden-brown and puffy.
Serve warm with tomato-caramelized onion chutney for dipping.