Caramelized Red Onion and Mushroom White Cheddar Flatbread

Prep Time
15 mins
Cook Time
12 mins


  • 1 puff pastry thawed according to package directions
  • 2 tbsp olive oil separated
  • 1 pint shitake mushroom cleaned
  • 1/2 red onion sliced
  • 2 tsp dijon mustard
  • 1 tsp garlic diced
  • 4 ounces sharp white cheddar
  • 4 sprigs fresh thyme leaves
  • salt and pepper to taste


  1. Preheat oven to 400°F.
  2. While oven is preheating, bring a skillet to medium high heat and cook mushrooms with 1/2 TBSP olive oil until softened, about 5-8 minutes. If the oil disappears in the pan while cooking, add 1 tbsp water. Once Mushrooms are softened, remove from heat and set aside.
  3. Over medium high heat, add 1/2 tbsp olive oil and red onion and cook until the red onion is softened. Remove from heat and turn off grill.
  4. Using the remaining 1 tbsp olive oil, cover the base of the puff pastry with oil out to the edges. Use a fork to prick the pastry all over to keep it from puffing up too aggressively in the oven.
  5. Add your dijon and garlic to the oiled puff pastry.
  6. Next, evening distribute the mushrooms and red onion. Cover with white cheddar, and then season with fresh thyme, salt and pepper.
  7. Bake in oven for 10-12 minutes until the puff pastry is golden brown.
  8. Remove and let cool completely, roughly 10 minutes, until cutting and serving.