Cook pasta in 2-3 l boiling salted water (1 teaspoon salt per litre) according to package instructions and boil eggs for about 8 minutes until hard.
Clean, wash, spin-dry and possibly chop the arugula smaller. Wash chives, dab dry, cut into rings. Mix crème fraîche, milk, horseradish, lemon peel, lemon juice and chives.
Season with salt, pepper and 1 pinch of sugar.
Quench, peel and dice the eggs. Drain the pasta, rinse with cold water for a few minutes and drain. Mix both with the sauce.
Cut the trout filets into pieces. Fold in with rocket salad. Season to taste again.