Caramelized Onion Tarts - cooking recipe

Ingredients

6 tbsp (3/4 stick) butter
2 tbsp olive oil
3 medium onions, thinly sliced
2 tbsp balsamic vinegar
2 tbsp brown sugar
2 sheets frozen puff pastry, thawed
4 oz sliced pepperoni
1 cup crumbled feta cheese
None None Baby spinach and oregano leaves, to serve

Preparation

Preheat the oven to 350\u00b0F. Line 2 baking pans with parchment paper.
Heat butter and oil in a large skillet on medium heat. Saute onions 15-20 mins, stirring occasionally, until softened and lightly golden. Add vinegar and sugar. Cook, stirring, 4-5 mins until liquid evaporates and sugar caramelizes.
Place pastry sheets on prepared pans. Spread onions on each sheet, leaving 1/2-inch border. Top with pepperoni and feta.
Bake 20-25 mins, until pastry is crisp and golden.
To serve, cut each tart into quarters. Sprinkle with spinach and oregano leaves.