Melt the sugar over medium heat in a large sauté pan, about 5 minutes.
Add the vinegar, then the olive oil, butter, and rosemary.
Lay the endive in on top, cut side down.
Sprinkle with salt and pepper, cover with foil, and cook over medium-low heat, turning a few times, until very soft and darkly caramelized, about 45 minutes.
Uncover, and continue cooking 15 minutes to reduce the liquid.
Pour over the wine, and reduce the pan juices to a glaze, 3 to 5 minutes.
Heat the oven to 400ºF/200ºC.
Divide the caramelized endive among six non-stick muffin tins.
Roll out the pastry and cut out six rounds to fit the top of the muffin moulds.
Place a round on top of each mould, tucking the pastry down in around the endives, like a blanket.
Bake until the pastry is golden and puffed up, about 20 minutes.
Flip out the baby tarts onto a cutting board.
Serve straight from the board at the table, along with an arugula or frisée salad.
*The quantity of endives needed will depend on size of the endives, obviously.
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