Step 1

Preheat the oven to 425ºF.

Step 2

Heat the olive oil in a medium frying pan over medium-low heat. Add the onions, salt, and pepper, and cook for 15 minutes, stirring occasionally. The heat should be low enough that the onions sizzle quietly but don't brown too quickly. Add the sugar (if using) and continue to cook for another 10 to 15 minutes, until the onions are dark golden and a darker brown crust begins to form on the bottom of the skillet.

Step 3

Add a splash of water to the pan. It will bubble furiously, picking up the browned bits. Continue to simmer until the water has evaporated but the onions haven't begun to brown up the bottom of the pan again, about 5 minutes. Turn off the heat.

Step 4

Brush a bit of olive oil on each flatbread. Scatter the onions evenly over each flatbread and crumble a quarter of goat cheese on each. Bake for about 8 minutes, until the cheese is beginning to melt and the flatbread gets slightly crisp.

Step 5

Remove from the oven, sprinkle a pinch of Maldon salt and the basil over the top of each bread, and cut into pieces. Serve warm.