Preheat the oven to 220C/425F/Gas 7.
First make the sauce base. Place the olive oil into a small pan over a low heat. Add the coriander seeds, shallots and garlic and cook gently for ten minutes without colouring. Remove the garlic clove from the sauce, then stir in the chopped tomatoes, a good squeeze of lemon juice (keeping some back for drizzling on the salmon) and 2 tbsp of the chopped parsley and set aside while you prepare the salmon.
To make the herb crust, place the oats, oatmeal, chives, the remaining parsley, 1 tablespoon of lemon zest and egg in a food processor and blitz for 20-30 seconds until damp and crumbly-looking.
Next heat the oil in an ovenproof non-stick frying pan over a high heat. Season the salmon fillets and place into the hot pan, skinned side uppermost. Sear the salmon for one minute then turn over. Quickly press the herb mixture on top of the salmon, drizzle with lemon juice, then transfer to the oven and cook for 4-5 minutes (depending on thickness), until the salmon is just cooked through and the crust is golden and crisp.
When cooked remove from the oven and place a salmon steak onto each serving plate, spooning the sauce around. Serve with buttered new potatoes.