Mix sun-dried tomatoes with vinegar in a bowl, pour boiling salted water over and let rest for 20 minutes. Drain, let cool and finely chop tomatoes.
Drain artichoke hearts and chop finely. Drain tuna and tear into bite-size pieces with a fork. Rinse parsley, pluck leaves from stems and finely chop leaves. Chop chives.
Mix mayonnaise in a bowl with creme fraiche and lemon juice until smooth. Add tomato, leek and artichoke, mix, add tuna and herbs and season with salt and pepper.