For the salmon, place the white wine, white wine vinegar, stock and sage leaves into a saucepan and heat together until simmering.
Simmer until the liquid has reduced to half its original volume.
Add the salmon to the saucepan and reduce the heat. Poach the fish for 6-8 minutes, or until the salmon is cooked through.
For the tomato sauce, place the garlic, double cream and tomatoes into a small saucepan and simmer for five minutes, until the sauce has thickened slightly.
Carefully remove the fish from the cooking liquor with a slotted spoon and place onto a serving plate.
To serve, spoon the tomato cream sauce around the edge of the salmon and garnish with dill.