Puff pastry tarts have a reputation for going soggy in the middle, and the reputation is deserved – if you skip the one step that prevents it. Slice the tomatoes, salt them, and let them sit on paper towels while you do everything else. The salt pulls the water out. That water is what turns a shatteringly crisp base into something you have to eat with a spoon.

Everything else is straightforward. Dijon on the pastry, Gruyere over the Dijon, tomatoes over the cheese, thyme over the tomatoes. Thirty minutes in a hot oven.

What You Need

• 8 Roma tomatoes
• 1 tsp kosher salt (for draining)
• 1 sheet all-butter puff pastry, thawed
• 1 egg, beaten (egg wash)
• 2 tbsp Dijon mustard
• 1 cup Gruyere, grated
• 1 garlic clove, minced
• 1 tsp fresh thyme leaves
• 2 tbsp extra-virgin olive oil
• 1/4 tsp freshly ground black pepper
• Flaky sea salt, to finish
• 1/4 cup fresh basil, torn (to serve)

How to Make It

Salt the tomatoes first. Slice into 1/4-inch rounds, lay in a single layer on paper towels, sprinkle with kosher salt, and top with another layer of paper towel. Leave them while you do everything else. This step is not optional.

Preheat the oven to 400°F. Line a baking sheet with parchment. Unfold the pastry onto the parchment. Score a border about 3/4-inch from the edge – don’t cut all the way through. Prick the inner rectangle all over with a fork. Brush the border with egg wash.

Blind-bake the pastry for 12-14 minutes, until the border is puffed and lightly golden. If the center has puffed up, press it back down gently with the back of a spoon. Let cool a few minutes.

Build the tart. Spread the Dijon evenly over the inner rectangle. Scatter the Gruyere over the mustard, then add the minced garlic and half the thyme. Pat the tomato slices firmly dry – get them as dry as you can – then shingle them over the cheese in slightly overlapping rows. Drizzle with olive oil, scatter the remaining thyme, grind black pepper over the top.

Bake for 25-30 minutes, until the tomatoes are starting to caramelize at the edges, the cheese is bubbling, and the pastry is deeply golden underneath. Tent loosely with foil if the edges brown too fast.

Rest for 5 minutes before cutting – lets the cheese set so it slices cleanly. Finish with flaky salt and torn basil. Cut into squares.

Notes

A green salad with a sharp vinaigrette is the right pairing.

Goat cheese variation: swap in 4 oz soft goat cheese mixed with a splash of cream, spread over the Dijon instead of Gruyere. Tangier, more rustic.

Leftovers: reheat at 350°F for 8 minutes. Skip the microwave.

Wine: a chilled rose or a crisp Sancerre.