Step 1

Heat oven to 200C/180C fan/gas Rub the pork with a tbsp of oil, add some seasoning, then seal the outside of the meat all over in a hot frying pan. Transfer the pork to a baking sheet, brush the outside with the mustard, then press on half of the tarragon and cook for 20 mins. Remove from the oven and cover with foil for 5 mins.

Step 2

Meanwhile, cook the lentils in the stock until just tender, about 12 mins, drain, then toss with the remaining olive oil, half the lemon juice and the apple.

Step 3

To make the aioli, mix the mayo, garlic, lemon zest and remaining juice and tarragon with some seasoning, then set aside. Slice the pork into thick slices and serve on a platter with the lentils, a bowl of aioli to dip into and some green beans.