Pour the vermouth into a cup and stir in the dried herbs. Put to one side.
Heat the butter and garlic oil in a small frying pan in which the two salmon fillets will fit snugly. When it begins to sizzle, add the salmon and cook, hump-side down, for two minutes.
Turn over the salmon, add the vermouth with its herbs and, once it comes to a bubble, cook for a further two minutes. Remove the salmon fillets to a couple of plates and then stir the cream into the pan, seasoning to taste.
If desired, add some chopped fresh tarragon or chives to the pan and pour the pale, herb-flecked sauce over the salmon pieces.
