Christmas upside-down tart with shallots, chestnuts and blue cheese with rosemary honey

Instructions

1. 1

   Preheat the oven to 200°F/95°C for 5 minutes to take the chill off if your kitchen is very cold, then set it to 400°F/200°C for baking. Lightly grease a 23 cm/9 in round pan or ovenproof skillet with a little of the butter.

2. 2

   Heat the butter and olive oil in a large skillet over medium heat. Add the shallots, salt, and black pepper, and cook for 10 minutes, stirring gently, until they start to brown around the edges.

3. 3

   Add the honey, balsamic vinegar, chopped rosemary, and thyme leaves. Cook for 5 more minutes over medium-low heat until the shallots are glossy and lightly caramelized. Stir in the chestnuts and cook 2 additional minutes so they absorb the flavors. Remove from the heat.

4. 4

   Arrange the shallots and chestnuts evenly over the bottom of the pan. Sprinkle the crumbled blue cheese and toasted walnuts on top. Add a few whole rosemary leaves for a more festive finish.

5. 5

   Roll out the puff pastry and, if needed, trim it into a circle slightly larger than the pan. Lay it over the filling and tuck the edges in carefully. Cut 3 small slits in the top to let steam escape.

6. 6

   Brush the pastry with the beaten egg. Bake at 400°F/200°C for 25 to 30 minutes, until the pastry is puffed and deeply golden brown.

7. 7

   Remove the tart from the oven and let it rest for 10 minutes so the juices settle and the glaze is not too runny.

8. 8

   Run a knife around the edge of the pan, place a large plate on top, and carefully invert the tart. Serve hot or warm, making sure each portion includes shallots, chestnuts, blue cheese, and walnuts.