Cut the salmon into about 12 thin slices, then cut across into strips.

Melt the butter in a large frying pan and sauté the salmon for 1-2 minutes. Remove the salmon strips using a slotted spoon and set aside.

Add the spring onions to the pan and cook for 2 minutes. Stir in the cucumber and sauté for 1-2 minutes, until hot. Remove the cucumber and keep warm with the salmon.

Add the wine to the pan and let it bubble until well reduced. Stir in the cucumber, creme fraiche, half of the chives and season to taste with salt and pepper. Return the salmon to the pan and warm through gently. Sprinkle the tomatoes and remaining chives over the top. Serve at once.