Bite Sized Pissaladières

Cut each onion in half, then slice as thinly as you can. Put the butter into a large pan over a low-medium heat, and when it has melted, add the onions. Cook the onions for about 40 minutes, keeping the heat low and stirring regularly to stop them sticking, until they are soft and golden. When they’re ready, transfer them to a plate or tray to cool. While the onions are cooling, unroll the pastry and cut it into 24 squares. Lightly oil a large baking sheet (or two smaller ones); transfer the squares to the sheets, spacing them out well, then use a sharp knife to score a border around the edges of the squares, about 5mm in from each side. Brush the borders with beaten egg, then put the baking sheets in the fridge for 20 minutes.
When the 20 mins is nearly up, heat the oven to 180⁰C (Gas Mark 6). Once the pastry has chilled and the oven is ready, cook the squares for 8-10 minutes, until crisp and lightly puffed up. Remove the pastry squares from the oven and use a fish slice to transfer them to clean baking sheets (you can sit the squares on a cooling rack while you wash and thoroughly dry the original sheets to re-use them, if need be). Use a spoon to gently push down the risen middles of each pastry square, then take the prepared onions and place a teaspoon of onion on each square, spreading it to the inner border edges. Next, cut each anchovy fillet in half lengthways, then again widthways. Place two anchovy pieces on each square, crossing them over, then top with an olive half and a few scattered thyme leaves. Put the pissaladières back in the oven for 5-10 minutes, or until the pastry is golden and they are hot throughout. Best served warm.