This space is for the biggest of onion fans! Soft wedges of charred onion, jammy caramelised onions, oozing gruyere and puff pastry. It's absolutely everything you want from French onion soup, just less soupy!
Let's get those onions caramelised. In a saucepan, add a generous knob of unsalted butter, and 4 sliced onions. Add salt and pepper, and a bit of thyme, and cook these down for a minimum of 45 minutes on low.
In the pan we'll be making our tart, add the 4 tbsp of butter, and begin to melt. Cut 3 onions into quarters, and 1 in half, and arrange the quarters around the edge of the pan. Place the halved onion in the middle and sear of medium high for 10 minutes. After this add the brandy and stock, and cook down for another 10 minutes.
Turn off the heat, and add the caramelised onions on top of the onions in the pan. To this add the grated gruyere, and cover with our puff pastry sheet pocking a hole in the middle. (Top Tip: if you want an extra puffed crust, fold the puff pastry sheet in half, and roll it out to the size of your pan or dish. This will add a few more layers to your pastry.)
Brush with egg wash and bake in a preheated oven at 180°c, for 30/45 minutes, until the pastry has risen and become golden brown in colour.
Flip and serve with a handful of chopped chives!
