By Chef Amanda DeLaura
These onions become so divinely flavorful and sweet that the extensive time spent peeling, chopping, and caramelizing them becomes quickly overlooked. I used to make this for my family whenever we had a birthday or special occasion to celebrate. In reality, my five siblings always devoured it before my parents could get their hands on it. But to this day my family asks for this particular recipe when we’re on holiday together. I like to make my crust with spelt flour (an ancient grain) as it contains a lower gluten content than all-purpose wheat flour and also creates a nuttier, richer flavor. Lastly, onions are proven to contain high levels of quercetin, a powerful flavonoid, which supports heart health and prevents oxidative stress.
Onion Filling —
3 Tbsp crème fraiche
6 sweet onions, chopped
4 Tbsp butter (for sautéing the onions)
6 sprigs of thyme (for the sauté)
salt & pepper to taste
Spelt Dough —
1 1/4 cups spelt flour
1/2 cup butter, very cold and cut into small pieces
Pinch of salt
4 to 6 Tbsp water, ice cold
1 egg, slightly beaten
1. In a skillet or pan over medium-high heat, melt the 4 Tbsp butter with thyme and add the onions. Cook until softened, about 10 minutes. Reduce the heat to medium-low and cook until onions are golden, about 25 minutes longer. Remove from the heat, discard the thyme and stir in the crème fraiche. Season with salt and pepper and let cool.
2. Using a food processor, pulse the 1/2 cup butter into the flour till the texture resembles sand, working as quickly as possible. Add the water and stir with your hands until just mixed, working as little as possible. Gently press to form into a disk. Wrap in plastic and refrigerate for at least 30 minutes.
3. Preheat oven to 375ºF. Position the rack to the bottom of oven. On a floured workspace, roll out dough to a 12-inch disk and transfer to a baking sheet. Spread the onions on the dough, leaving a 1 ½ inch border. Fold the edge of the dough up and over the filling and brush the edge with the egg. Bake the tart on the bottom rack for about 40 minutes, until the dough is richly browned at the bottom. Transfer to the top shelf and bake for another 5 minutes. Let cool for 8 to 10 minutes.