1. Peel and chop the carrot, celery, and onion. Cut the leek lengthways, wash and cut into large pieces.

2. Wash the tongue and add to a pan of boiling water with the vegetables, bouquet garni, peppercorns and a teaspoon of salt. Return to a boil and then reduce the heat to the merest simmer. Leave to cook for two hours, or until the tongue yields when pierced with the tip of a knife.

3. Remove the tongue from the pan, leave to cool slightly, and then remove the skin, starting with the thicker part and working towards the tip. Trim the fat from the ends and remove any unsightly pieces. Return the tongue to the pan.

4. Preheat the oven to 120°C. Peel the potatoes and slice thinly with a mandolin. Heat the olive oil in a 24cm-diameter frying pan, and arrange the potatoes in a layer, overlapping them and completely covering the base of the pan. Season with salt. When the bottom of the potato layer is brown, turn and cook the other side. Cook one potato rosette for each person. Keep the potatoes warm in the oven while you prepare the rest.

5. Remove the root and thick part of the stems of the saltwort. Trim the tips of the asparagus leaving the tip plus around 2cm of the stalk. Bring some salted water to a boil and cook the tips for around 4 minutes, depending on the size. Wash the saltwort and add to the asparagus. Cook for a further two minutes and then drain.

6. Grind the pistachios and mix with the olive oil. Add a little salt. Leave the saltwort and asparagus to cool with some olive oil, lemon juice, and a little salt.

7. Arrange some slices of tongue with the saltwort and asparagus on top of the potato rosettes. Add the pistachio pesto and serve.