Serves 10 as an Appetizer, 4-5 as a Main Course
Extra-virgin oil for drizzling
½ tsp sea salt
½ tsp freshly ground pepper
½ tsp herbes de Provence
8–10 Roma or San Marzano tomatoes, cored and halved lengthwise
12 large cloves garlic, unpeeled
1 sheet frozen puff pastry (about ½ lb/250 g), thawed
2 tsp crème fraȋche
1 tsp Dijon mustard
Preheat the oven to 300°F (150°C). Place racks in the upper and lower thirds of the oven.
Drizzle just enough oil on a rimmed baking sheet to thinly coat the bottom. Sprinkle the salt, pepper, and herbes de Provence over the oil. Place the tomatoes, cut side down, on the baking sheet, rubbing them around to absorb the oil and seasoning.
Place the garlic cloves on a piece of aluminum foil, drizzle with some oil, and turn to coat evenly. Seal the foil into a packet and place it in a small baking dish.
Place the baking sheet with the tomatoes on the upper rack of the oven and the garlic on the lower rack. Roast the tomatoes until their skins slip off easily, about 15 minutes. Remove the baking sheet with the tomatoes from the oven and set aside to cool. Raise the oven temperature to 350°F (180°C) and continue to roast the garlic until soft and easily pierced with the tip of a knife, about 25 minutes longer. Set aside to cool.
When the tomatoes are cool enough to handle, remove and discard the skins, leaving the tomatoes on the baking sheet. When the garlic cloves are cool enough to handle, remove and discard the skins, leaving the cloves whole. The tomatoes and the garlic can be prepared a day ahead and stored, covered, in the refrigerator. Bring to room temperature before using.
Raise the oven temperature to 400°F (200°C).
On a floured work surface, roll the puff pastry into a rectangle about 10 by 13 inches (25 by 33 cm). Drape it over an 8-by-11½-inch (20-by-29-cm) rectangular fluted tart pan with a removable bottom and gently press the pastry into the pan, letting the edges hang over the sides. Using your fingers, tuck the excess dough under to make a folded rim that rises slightly above the sides of the tart pan.
Line the pastry with aluminum foil and add pie weights or dried beans. Bake on the middle rack of the oven until the exposed edges begin to turn golden, about 10 minutes. Remove the weights and foil. Prick the bottom of the pastry with a fork and continue to bake until the crust turns a pale bisque, about 3 minutes longer. If it puffs up, prick the puff with a fork to deflate it. Let the crust cool slightly.
Reduce the oven temperature to 375°F (190°C).
In a bowl, combine the crème fraîche and mustard. Using a spatula, spread the mustard mixture evenly over the bottom of the tart shell.
Arrange the tomatoes, cut side up, across the surface of the tart shell. Tuck the garlic cloves among the tomatoes. With a pastry brush, brush the tops of the tomatoes with juices from the baking sheet. Bake until the edges of the crust are puffed and deep gold and the bottom is cooked through, 15–20 minutes.
Remove from the oven. Let stand for 15 minutes. Slip a knife around the edges of the pan to loosen any clinging bits of pastry. Gently push on the bottom of the pan, nudging the sides loose. Slide the tomato tart onto a serving plate, cut into pieces, and serve warm.
Round out your meatless Monday dinner by pairing this tomato tart with a recipe for cauliflower steaks with capers, anchovies, and winter greens.