Chamosard asparagus gratin

Preheat the oven to 190°C.

Thinly slice the onions and leeks, peel the carrots and cut them into rounds.

Brown the onions, carrots and leeks in a pan with the butter for 5 to 7 minutes.

Peel the asparagus, then dice it into 4cm pieces.

Cook the asparagus tips for 2 minutes in boiling water, then set aside.

Add the asparagus pieces to the other vegetables, season with salt and pepper and deglaze with the Johannisberg. Leave to reduce for 2 to 3 minutes, then set aside.

Peel the potatoes and cut them into 2cm-thick slices.

Pluck the leaves from the rosemary sprigs and finely chop them.

Pour the milk and cream into a casserole and heat for 1 to 2 minutes, then season with salt and pepper. Add the chopped rosemary and the potato slices and leave to simmer over a gentle heat for 20 minutes, stirring from time to time to keep it from burning.

Add the vegetables to the mixture and pour into a gratin dish. Garnish with the tomatoes, cheese, and asparagus tips.

Put the dish in the oven and cook for 20 minutes at 190°C.