Preheat the oven to Gas Mark 8 (240°).
After removing the larger stems, put the herbs, the slices of bread without the crusts, and the peeled and halved shallots in a food processor bowl. Mix this to make a firm dough.
Add the mustard with your hands onto the entire surface of the meat, season generously, and then spread the herb paste by pressing it until it sticks.
Cook the meat sprinkled with a dash of olive oil in the oven for 25 minutes. Then let it stand for 10 minutes with the oven switched off.