- 1 leeks
- 5 onions
- 8 tablespoons brown sugar
- 8 tablespoons butter
- 4 tablespoons balsamic vinegar
- puff pastry
- Cut the white part off of the leeks and cut into slices.
- Slice the onions thinly.
- Heat a little olive oil in a skillet on high heat and add the leeks and onion.
- Cover and reduce the heat, simmer for 15 minutes, stirring occasionally.
- Spread 4 tablespoons of brown sugar on the bottom of a pie pan. Add the sliced butter.
- Preheat oven to 420F
- Place the pie pan in the oven just to melt the butter and then remove it.
- Uncover the skillet and turn up the heat.
- To the skillet, add 4 tablespoons of sugar and 4 tablespoons of vinegar, sear the leeks and stir.
- Spread this mixture out well in the pie pan.
- Cover with the puff pastry and bake for about 15 minutes.
- Unmold the tatin on a large plate by flipping it over.