Ingredients:
1 anchovy fillet, finely chopped
2 tablespoons extra virgin olive oil
15 cherry tomatoes
¼ teaspoon kosher salt
¼ teaspoon freshly ground black pepper
2 tablespoons unsalted butter
1 tablespoon extra-virgin olive oil
2 large yellow onions, thinly sliced
1 ½ cups crimini mushrooms, sliced
1 ½ cups baby button mushrooms, sliced
2 cloves garlic, minced
2 sprigs fresh thyme
1 teaspoon fresh thyme leaves or ½ teaspoon dried thyme leaves
½ teaspoon kosher salt
¼ teaspoon freshly ground black pepper
1 sheet frozen puff pastry, thawed (check directions on package for thawing guidelines)
1 egg, beaten with 1 teaspoon water
12 to 15 good-quality black olives (Kalamata, oil-cured, Niçoise), halved lengthwise

Directions:
Set oven to broiler function (approx. 500-500 degrees F).

In a medium bowl, combine the chopped anchovy with olive oil, add the cherry tomatoes and toss to combine. Sprinkle with salt and pepper and toss again until evenly distributed. Place the tomatoes on a baking sheet and broil for 4 to 5 minutes until the skins just begin to split. Watch carefully to prevent browning. Remove from oven and allow to cool. Once cool, slice tomatoes in half and set aside.

Preheat oven to 400 degrees F.

In a medium sauce pan, melt the butter over medium heat and add the olive oil. Add the onions, mushrooms, garlic and thyme, stirring to combine. The onions will appear to overflow the pan but will quickly reduce below the rim.

Stir in the kosher salt and black pepper, partially cover pan and cook, over medium-low heat until the onions are softened and golden brown, about 25 to 30 minutes. Remove pan from heat and discard the thyme sprigs.

Place the puff pastry on a lightly floured surface and roll out to desired size. If using a tart pan, gently press the dough into place, pressing along the bottom and edges. If using a baking sheet, place the dough on the sheet leaving at least an inch between the edges. Use a fork to prick the pastry all over and refrigerate until ready to assemble.

Spread the onion mixture evenly over the center of the pastry, leaving a one-inch border free of topping. Brush the border with the egg wash. Place sheet in the oven and bake for 10 minutes, then remove from oven and sprinkle with the halved tomatoes and olives.

Return tart to oven and continue baking for 10 to 15 minutes, until the edges and bottom are golden brown. Slice and serve warm or at room temperature. Leftovers may be refrigerated for at least 2 days.