1 pound Heirloom tomatoes (sliced into 1/2-inch thick)
3 tablespoons olive oil
2 tablespoons unsalted butter
1 small red onion (sliced into 1/4-inch rings)
1 teaspoon thyme leaves
1/4 cup blue cheese (crumbled, plus more to garnish)
2 tablespoons breadcrumbs
1 sheet puff pastry (thawed)
kosher salt and freshly ground black pepper (to taste)

Preheat the oven to 425║F.
On a sheet tray lined with a cooling rack, arrange the tomato slices.
Season both sides of the tomatoes and allow to sit for 30 minutes to remove moisture.
After 30 minutes, blot both sides of the tomatoes with a paper towel to soak up any remaining moisture.
In the meantime, gently roll out the puff pastry to fit the diameter of a 12-inch pan.
Place a nonstick, 12-inch sautÚ pan over medium-high heat. Add 1 tablespoon of oil and butter.
Once the butter has melted, add the red onion and a pinch of salt.
SautÚ until the onions begin to turn golden-brown, about 5 minutes.
Add the thyme leaves to the onions. Remove pan from heat.
Sprinkle the blue cheese evenly on top of the onions.
Arrange the tomato slices on top, in a circular pattern, overlapping them slightly.
Season the tomatoes with salt and pepper. Sprinkle the breadcrumbs on top in an even layer.
Drizzle 1 tablespoon of olive oil over the breadcrumbs and place the puff pastry on top.
Place in the oven and bake for 20-25 minutes until golden brown, puffed and crisp.
Remove from the oven and allow to cool for 5 minutes before inverting the tart onto a plate.
Garnish with some more blue cheese and fresh thyme leaves.
Slice into 6 pieces. Serve warm or at room temperature.

Michael Symon, The Chew