Put 2 tsp fennel seeds* and a pinch of salt in a mortar and pestle (see Kitchen notes) and pound to a powder. Sprinkle 1 tsp fennel mixture over the salmon, season with salt and pepper and rub to coat all over. Thinly slice the onion (see Kitchen notes). Halve the wholemeal rolls. Halve 1 garlic clove.
Step 2 — Cook salmon
Preheat the grill to high. Heat 2 tsp olive oil in a small frypan over high heat. Cook the salmon, skin-side down, for 3 mins or until the skin is crisp and golden. Reduce the heat to medium-high, turn and cook, flesh-side down, for a further 2-3 mins until just cooked or cooked to your liking. Remove from the pan.
Step 3 — Make dressing
Meanwhile, put 1 tbs olive oil, 1 tbs white wine vinegar, 2 tsp wholegrain mustard and 2 tsp honey in a large bowl, season with salt and pepper and whisk to combine. Add the onion and toss to combine.
Step 4 — Make fennel salt
Put the wholemeal rolls on an oven tray, spray or brush with olive oil and grill for 1-2 mins until lightly toasted. Meanwhile, put the remaining fennel mixture and 1 tsp sea salt flakes in a bowl, season with pepper and stir to combine.
Step 5 — Serve up
Rub the warm rolls with the cut side of the garlic clove. Add the salad leaves to the onion mixture and toss to combine. Divide the salmon and salad among plates and scatter the salmon with the fennel salt. Serve with the garlic rolls and enjoy!
Step 6 — Kitchen notes
We used a mortar and pestle to grind the fennel seeds. If you don't have one, finely chop with a large knife or process in a small food processor instead. ~ Raw onion can have a strong taste if chunky, so very thinly slice with a sharp knife or use a mandoline if you have one. If you aren't keen on raw onion, cook it in the pan after you have cooked the salmon.