Upside-Down Onion Tartlets

Name: Upside-Down Onion Tartlets
Prep time: 10 min
Total time: 40 min
Yield: 6 serving(s)
Ingredients: 1/2 package puff-pastry dough, thawed; 4 tbsp. Maille Honey Dijon Mustard, divided; 1 tbsp. olive oil; 1 tbsp. honey, plus more for drizzling; 1/2 tsp. fresh thyme, finely chopped, plus leaves for garnish; 1 garlic clove, grated; 3/4 tsp. kosher salt, divided; 1/4 tsp. black pepper; 1 large red onion, cut into six ⅛-inch-thick rounds; 1/2 c. mayonnaise; 1 tbsp. fresh lemon juice; 3/4 tsp. cayenne pepper; Flaky salt, for garnish (optional)

Sweet, tangy, and totally delicious.

By Kaitlin WaynePublished: Nov 26, 2024

savory pastries topped with caramelized onions on a black tray

Joseph De Leo

Yields:

6 serving(s)

Prep Time:

10 mins

Total Time:

40 mins

Cal/Serv:

232

Jump to recipe

These tartlets have been trending for good reason: They’re easy to make, they’re super-versatile, and they taste great, thanks to all the caramelized bits.

This version with red onion is a stunner that holds the onion’s rosette shape after baking. For a pop of flavor, whip up an extra dip using Maille Honey Dijon Mustard. Both the onions and the mustard have bite tempered by sweetness—zing that sings!

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Ingredients

1/2
package puff-pastry dough, thawed
4 Tbsp.
Maille Honey Dijon Mustard, divided
1 Tbsp.
olive oil
1 Tbsp.
honey, plus more for drizzling
1/2 tsp.
fresh thyme, finely chopped, plus leaves for garnish
1
garlic clove, grated
3/4 tsp.
kosher salt, divided
1/4 tsp.
black pepper
1
large red onion, cut into six ⅛-inch-thick rounds
1/2 c.
mayonnaise
1 Tbsp.
fresh lemon juice
3/4 tsp.
cayenne pepper
Flaky salt, for garnish (optional)

Directions

1. Step 1Preheat the oven to 425°. Line two baking sheets with parchment paper.
2. Step 2Roll out the puff-pastry sheets slightly until thin, about 1/16 inch, then cut into six 4-by-4-inch squares. (You will need to patch together scraps for the last two.) Transfer to one of the prepared sheets; set aside.
3. Step 3In a small bowl, combine 1 tablespoon Maille Honey Dijon Mustard, olive oil, honey, thyme, garlic, ½ teaspoon kosher salt, and pepper. On the second baking sheet, make 6 equally spaced pools from this mixture, about 1½ teaspoons each. Top each pool with a round of onion. Top each onion with a square of puff pastry, pressing down slightly around edges of onion to adhere pastry to parchment.
4. Step 4Bake for 25 to 30 minutes, or until the pastry is golden brown and cooked through, and the onion is slightly caramelized. Let cool for a couple of minutes, then very gently flip each over to reveal the onion.
5. Step 5Meanwhile, in a medium bowl, whisk together remaining 3 tablespoons Maille Honey Dijon Mustard, mayonnaise, lemon juice, cayenne, and remaining ¼ teaspoon salt.
6. Step 6Sprinkle tartlets with thyme leaves and flaky salt (if using), drizzle with honey, and serve, alongside dipping sauce.