Preheat the grill to the highest setting. To make the dressing, peel and ﬁnely chop the shallot, or rinse, trim and ﬁnely chop the scallions, and place them in a small bowl. Rinse, dry and chop the dill or celery leaves and add them to the bowl with the vinegar, walnut oil, salt and pepper. Mix well and set aside.
Grease the grill pan with half the canola oil and lay the trout ﬁllets on top, skin sides down. Season them with salt and paprika. Grill the ﬁsh for 5-8 minutes, on one side only, until the ﬂesh is opaque in the centre and delicately brown at the edges.
While the ﬁllets are cooking, heat the remaining oil in a small frying pan and gently fry the walnuts, shaking and stirring constantly so that they colour but do not burn. Drain them on kitchen paper, then chop them roughly.
Rinse and dry the salad leaves and arrange on four plates. Lay a ﬁllet of trout on each. Stir the dressing, spoon it over the ﬁsh, and scatter the walnuts on top.
Cook's tip: New potatoes go well with the ﬂavours of this dish. Start boiling before you start cooking the trout.
Each serving: 37 g protein, 33 g fat of which 4 g saturates, 1 g carbohydrate, 451 Calories