The colder air in the evening has set in here in Provence. The vines are all shifting from their vibrant green to the warm tones of autumn: burnished gold and scarlet red. The autumnal shift makes me want to cook with slower, sweeter flavors.
Onion tart is one of those recipes that has anchored Provençal cooking for centuries. It isn't a grand dish; in fact, its origins are modest. Farmers would often bake an onion tart early in the day and let it rest while they worked the fields.
There is a favorite story from a village near Aix-en-Provence of a mayor whose speeches were so long, the tart meant for lunch would completely cool before he finished. No one minded, since an onion tart often tastes even better that way. The onions become silky and soak in the savors of the dish. To this day, many Provençal cooks prefer to serve an onion tart at room temperature.
Our recipe today is a nod to that tradition: halved onions, slow-cooked until caramelized and opened like soft roses, in a creamy custard base with thyme.
Ingredients (serves 6–8)
• 1 sheet pâte feuilletée (ready-rolled or homemade)
• 6–8 medium onions (yellow or red, or a mix for color)
• 2 tbsp olive oil
• 1 tbsp butter (optional, for extra glaze)
• 1 tsp sugar
• 1 tbsp balsamic vinegar (or white wine vinegar)
• Salt and pepper
• 1 tsp fresh thyme leaves (or herbes de Provence)
• 2 eggs
• 150 ml crème fraîche (you can use a mix of cream and milk if preferred)
• A small handful of grated cheese (optional: comté, gruyère, or goat cheese)
Step 1: Prepare the Onions
1. Halve the onions through the root so they hold their shape. Peel carefully without separating the layers.
2. Heat olive oil (and butter, if using) in a wide skillet over medium-low heat.
3. Place onions cut side down. Sprinkle with sugar, salt, pepper, and thyme.
4. Cook gently for 20-25 min, letting the cut sides caramelize without moving too much.
5. Deglaze with balsamic vinegar, add a splash of water, cover, and let steam another 10 min until tender.
Step 2: Blind Bake the Pastry
1. Preheat oven to 180 °C (350 °F).
2. Line a tart pan with the pâte feuilletée. Prick the base with a fork.
3. Place parchment and baking weights (or dried beans) on top.
4. Blind bake for 10 minutes. Remove weights and bake another 5 minutes, just to set the base.
Step 3: Make the Custard
1. In a bowl, whisk together eggs, crème fraîche, salt, pepper, and thyme.
2. (Optional) Stir in half of the grated cheese.
Step 4: Assemble the Tart
1. Pour the custard base into the pre-baked tart shell.
2. Arrange the onion halves cut side up like flowers, nestling them into the custard.
3. Sprinkle the remaining cheese over the top (optional).
Step 5: Bake
• Bake for 25–30 minutes, until the custard is set, the pastry is golden, and the onions look beautifully caramelized.
• Let cool slightly before serving.
Serving Tip
Drizzle with a thread of good olive oil and scatter fresh thyme leaves on top. Serve warm or at room temperature with a crisp green salad and a chilled rosé from Côtes de Provence.
