French Onion Pastry Bites are just what you need to impress your friends. An easy make ahead appetizer just in time for the Super Bowl. Be warned, they are addictive!
1. Heat butter and olive oil in a skillet over medium heat. When butter has melted, add onions and coat with butter mixture. Cook, undisturbed until onions begin to soften, about 4 minutes. Add thyme, mustard, sugar and salt and pepper, stir to combine. Cook covered, stirring about every 4 minutes until they are golden brown, about 16-20 minutes. Reduce heat if they begin to brown too quickly.
2. Add chicken stock, cook stirring until liquid is incorporated, about a minute. Remove from heat and let cool slightly.
3. Preheat oven to 375º. Place parchment paper on baking sheet.
4. Roll out both pastry sheets into an equal sized square.
5. Spoon 1 teaspoon of onion mixture in 36 squares about 1 inch apart. You will have 6 rows across and 6 down. Top with some cheese. Top with second sheet of puff pastry and using your fingers, press the top layer around the filling. Using a pizza cutter, cut into 36 squares and pinch the sides to seal. Use a fork to press the edges together. Place about 2 inches apart on prepared baking sheet.
6. Brush with slightly beaten egg and sprinkle with salt and pepper.
7. Bake for 12-15 minutes until slightly golden, let cool before serving.