Sweet Onion Tarte Tatin Recipe

Combine vinegar, water, sugar and sea salt in a small saucepan and bring to a gentle simmer over medium heat, stirring until the sugar dissolves.

Add peeled cipollini onions and simmer gently for 8–10 minutes until onions are just tender and have absorbed some pickling liquid. Remove from heat and let cool to room temperature (they will continue to soften).

Transfer onions and pickling liquid to a jar or bowl, add 1 tablespoon olive oil, stir, then refrigerate until ready to serve. Bring to room temperature before plating.

Preheat oven to 200°C (400°F).

Peel and halve the yellow onions lengthwise. Slice each half into 3–4 thick wedges so pieces hold shape when caramelized.

Heat a 10–12 inch ovenproof skillet (preferably cast iron) over medium heat. Add 1 tablespoon olive oil and 2 tablespoons butter. When butter foams, add the onion wedges in a single layer cut-side down; work in batches if necessary to avoid crowding.

Sprinkle 3 tablespoons sugar evenly over the onions in the skillet. Allow onions to cook undisturbed 6–8 minutes so the sugar and butter form a light caramel and onions brown on the cut sides.

Season with 1 teaspoon sea salt, 1 teaspoon black pepper and scatter 1 teaspoon fresh thyme leaves over the onions. Add 1 tablespoon apple cider vinegar to deglaze and gently toss to coat. Cook 1–2 more minutes until caramel is glossy and onions are tender but not falling apart.

Arrange the caramelized onion wedges tightly in a circular pattern in the skillet, cut side down, building up a decorative mound that will become the top of the tarte when inverted.

Melt the remaining 2 tablespoons butter in a small saucepan or microwave and spoon it around the edges of the onions so the pastry will brown evenly.

Roll out the thawed puff pastry on a lightly floured surface to roughly a 12-inch circle. Trim if necessary to 1–2 cm larger than the skillet rim. Prick the center lightly with a fork to release steam (avoid pricking edges).

Beat the egg with 1 teaspoon cold water to make an egg wash. Brush the edge of the pastry with egg wash then carefully drape the pastry over the onions, tucking the edges down around the inside of the skillet so they encase the filling.

Brush the top of the pastry with remaining egg wash and cut 2 small slits in the center to vent steam.

Transfer the skillet to the preheated oven and bake 22–28 minutes until the pastry is puffed and deep golden brown.

Remove from oven and let rest 5 minutes. Carefully place a large plate or cake board over the skillet, holding firmly, and invert quickly but cautiously to release the tarte tatin so the caramelized onions are on top. If any onions stick, gently lift them into place. Spoon any accumulated juices over the top.

While the tarte bakes, whisk together creme fraîche, lemon juice, 1 teaspoon honey, 1 teaspoon extra-virgin olive oil, 1/2 teaspoon salt and 1/4 teaspoon black pepper in a small bowl until smooth. Taste and adjust seasoning.

Toss mâche lightly with a small drizzle (about 1 tsp) of olive oil and a pinch of salt just before plating to keep leaves fresh.

Cut the inverted tarte Tatin into 6 equal wedges for small plates.

Place a wedge on each plate. Spoon 1–2 tablespoons of creme fraîche alongside or dolloped atop each wedge.

Arrange a small handful (about 20 g) of lightly dressed mâche beside the tarte on each plate.

Top with 1–2 pickled cipollini onions per plate, sliced or whole depending on size, spooning a little pickling liquid over the onions if desired.

Garnish each plate with a small thyme sprig and a light sprinkle of flaky sea salt. Serve warm.