Ingredients
Pastry Base
- 3/4 cup flour (all-purpose or part wholewheat pastry flour)
- 3 tbsp unsalted butter (cold, cut into chunks)
- 1 pinch salt
- 2 tbsp cold water (adjust as needed)
Filling
- 12 oz onion (approximately 1 large onion, halved and thinly sliced)
- 1 tbsp butter
- 1 pinch salt
- 1 pinch sugar
- 1/2 tsp dried thyme (or a little more if using fresh)
- 2 oz soft goat cheese
- 1 egg
- 1/4 cup heavy cream (double cream)
- Pinch of salt and pepper (for egg mixture)
Salad (optional, for serving)
- 2 handfuls arugula (rocket or substitute with sliced romaine or watercress)
- 12 green grapes (halved)
- 1/4 bulb fennel (thinly sliced)
- 1 tsp olive oil
- 1 tsp balsamic vinegar
Instructions
- Prepare Pastry Base: Place the flour, salt, and cold butter chunks into a food processor and pulse until the mixture forms coarse crumbs, or use a pastry cutter by hand. Gradually add cold water until the dough clumps together. Roll out the dough on a floured surface to about 3mm (1/8 inch) thickness.
- Set Up Tart Pans: Lightly grease three 5-inch (12 cm) tart pans unless they are non-stick. Press the rolled pastry into the pans, trimming excess along the edges. Place pans on a baking sheet and chill while preheating the oven.
- Blind Bake Pastry: Preheat oven to 375°F (190°C). Line pastry cases with parchment paper and fill with baking beans. Bake for 15 minutes until edges are dry but not browned, remove beans and parchment, then bake another 2 minutes to dry the base. Remove and cool.
- Caramelize Onions: Heat butter in a medium-large skillet over medium heat. Add sliced onions and cook slowly, stirring occasionally, to soften and reduce. Lower the heat if browning happens too quickly. Cook about 30 minutes until onions are very soft and gently browned.
- Season Onions: As the onions brown, stir in salt, sugar, and thyme. Cook for an additional 1-2 minutes until well combined and onions are deeply caramelized.
- Prepare Egg Mixture: Whisk together egg, heavy cream, a pinch of salt, and pepper until well combined.
- Assemble Tarts: Divide the caramelized onions evenly among the pastry bases. Crumble goat cheese over the onions, then pour the egg-cream custard over the top, ensuring it evenly covers the filling. Optionally, sprinkle extra thyme and pepper on top.
- Bake Tarts: Bake in the preheated oven for 20 to 25 minutes until the top is lightly browned and the custard is set.
- Prepare Salad: While tarts bake, toss arugula, halved grapes, and thinly sliced fennel with olive oil and balsamic vinegar. Set aside.
- Serve: Allow tarts to rest for a minute after baking, then carefully remove from pans. Serve warm or at room temperature alongside the fresh salad.
Notes
- You can adjust water quantity for pastry dough to achieve the right consistency; it should hold together without being sticky.
- Using part wholewheat flour adds nuttiness and fiber but can make the crust slightly denser.
- Add a little extra butter when caramelizing onions if they start sticking to the pan.
- The salad is optional but adds a refreshing contrast to the rich tart.
- If you want a sharper thyme flavor, use fresh thyme and increase quantity slightly.
- Blind baking the pastry ensures the base does not become soggy from the custard filling.
- These tarts are best enjoyed the same day but can be served at room temperature without losing flavor.
- Prep Time: 15 minutes
- Cook Time: 35 minutes
- Category: Savory Tart
- Method: Baking
- Cuisine: French-inspired
- Diet: Vegetarian
