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The starter, Chic bistro

Tomato and mustard tart

This tomato and mustard tart is a summer starter for 6 made with puff pastry, ripe tomatoes, and gruyère. It takes 20 minutes of active work, the tomatoes drain in the morning, and the tart bakes just before guests arrive. It's very easy and costs about €1.50 per serving, and the key is patting the tomatoes dry so the pastry stays crisp.

A tomato and mustard tart coming out of the oven just before you sit down to eat smells like summer all through the house.

Tomato and mustard tart
For
6 people
Work
20 min
Total time
40 min
Prep
Finished at the last minute
Difficulty
Very easy
Cost per person
€1.50
Calories per person
310 kcalcalculated by Kiloach, your weight coach

This tart smells like summer the moment it comes out of the oven, thin crisp puff pastry under juicy tomato slices, mustard adding a gentle bite under melted gruyère. Fresh thyme gives it that outdoor dinner scent, and a pinch of flaky salt right out of the oven wakes everything up.

It's the starter you make for a dinner with friends on the terrace or to open a family meal in summer, when tomatoes are at their best. It leads nicely into grilled meat or simple fish, and kids tend to love it as a milder cousin of pizza.

The schedule

What happens when, so you can be with your guests instead of in the kitchen.

  1. The day before Nothing to do
  2. The same day 2 steps, 20 min
  3. Before the guests arrive 2 steps, 20 min
  4. When it's time to serve 1 step

In the morning, slice and drain the tomatoes, then cut and prick the pastry bases and keep them chilled. Just before guests arrive, assemble the tarts and bake them for 20 minutes. Pull them out, season, and serve right away while they're still warm and crisp.

The ingredients

6 people

Dairy

  • Puff pastry sheets 2
  • Grated gruyère 80 g

Fruits and vegetables

  • Ripe tomatoes 900 g
  • Fresh thyme 6 sprigs

Pantry

  • Strong mustardoften in the pantry 3 tbsp
  • Olive oiloften in the pantry 3 tbsp
  • Flaky saltoften in the pantry 1 pinch
  • Pepperoften in the pantry 1 pinch

Allergens Gluten, Mustard, Lactose

The recipe, moment by moment

The same dayDuring the day, whenever you get a moment.

  1. Slice the tomatoes thinly, salt them lightly, and let them release their water on paper towels. 20 min

    Flip them halfway through, they lose water from both sides.

  2. Cut 6 rounds or rectangles of pastry, prick them, and set them on parchment lined baking sheets, chilled.

    Keep the pastry well chilled until it goes in the oven, it rises much better.

Before the guests arriveThe last hour, right before the doorbell rings.

  1. Spread the mustard in a thin layer, scatter over the gruyère, then arrange the tomatoes in a rosette.

    Overlap the slices like roof tiles, they hold together and the tart looks better.

  2. Drizzle with olive oil, add the thyme, and bake at 200°C. 20 min

    Place the sheet on the lower rack so the bottom cooks as much as the top.

When it's time to serveThe final touches, right in front of your guests.

  1. Take the tarts out of the oven, add pepper and a pinch of flaky salt, then serve right away.

    These tarts don't wait, they're at their best warm and crisp.

Our tips to get it right

  • Pick firm, meaty tomatoes rather than very juicy ones like beefsteak types, they release less water and the tart stays neat.
  • Spread the mustard very thinly, a thick layer makes the tart too sharp and hides the tomato flavor.
  • If you don't have perforated parchment, prick the pastry well with a fork so it doesn't puff up unevenly in the oven.

The variations

  • Swap the gruyère for mozzarella for a stretchier, milder version.
  • For a mustard free version for kids, use a drizzle of olive oil and a little chopped basil added after baking instead.
  • Add a few pitted black olives or anchovies on top before baking for a more Mediterranean take.

What to serve it with

  • A green salad with a sharp vinaigrette
  • A chilled glass of rosé
  • Iced tomato juice for the kids

Storage

This tart is best eaten the same day, ideally warm from the oven, since puff pastry softens quickly. If you have leftovers, keep them in a sealed container in the fridge for up to a day and reheat briefly in the oven to crisp them back up.

Questions about this recipe

Can I use shortcrust pastry instead of puff pastry?

Yes, shortcrust works well and gives a more rustic, less puffy tart. The baking time stays about the same, just watch the color.

How do I keep the tart from getting soggy?

The trick is salting the tomatoes and patting them dry before laying them on the pastry. The gruyère underneath also helps by forming a barrier between the pastry and the juice.

Can I make this tart for more than 6 people?

Yes, just scale up the ingredients proportionally and use extra baking sheets. Keep the tomatoes in a single layer for even cooking.

What kind of mustard works best here?

A classic strong Dijon style mustard gives the best balance with the gruyère and tomatoes. Wholegrain mustard also works and adds a bit of texture.

Can a tomato and mustard tart be made ahead?

Partly, the finish happens at the last moment. The recipe needs 20 min of work in total, split up like this, the same day, 2 steps, before the guests arrive, 2 steps, when it's time to serve, 1 step.

How long does it take to make a tomato and mustard tart?

Allow 40 min in total, including resting and cooking time, of which 20 min is actual work. The recipe is rated "very easy".

How many calories are in a tomato and mustard tart?

About 310 kcal per person, for a recipe meant for 6 people. The calories are calculated by Kiloach, your kilo coach, the app that partners with Mon Chou.

How much does a tomato and mustard tart cost?

About €1.50 per person, that's €9.00 for 6 people, based on average supermarket prices.

What allergens does this recipe contain?

This recipe contains gluten, mustard, lactose. Remember to ask your guests about their allergies before putting your menu together.

To round out your menu

Build a menu
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450 kcalcalculated by Kiloach

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