Prepare the salmon: Cook the shallot with the olive oil in a skillet over medium heat, 2 to 3 minutes. Season the salmon with salt and pepper; add to the skillet. Add the wine, cover and cook over low heat until opaque, 3 to 4 minutes per side. Transfer the salmon to a plate and let the pan juices simmer, 2 minutes. Let cool.
Pulse the smoked salmon and butter in a food processor to make a coarse paste. Flake in the cooked salmon; add the pan juices, lemon juice, nutmeg and 1/4 teaspoon salt. Pulse until incorporated. Spoon into a bowl, cover and chill at least 1 hour.
Make the salad: Toss the tomatoes, sugar and a pinch of salt in a bowl. In a separate bowl, whisk the vinegar, mustard and 1/2 teaspoon salt, then whisk in the olive oil. Whisk in the cream, tarragon and chives. Toss in the tomatoes and season with salt and pepper. Serve with the salmon rillettes and bread.