Apple wash. Cut the fruit flesh in thin slices down to the core. Cut the slices into small cubes and sprinkle with lemon juice. Wash the chives, shake dry and cut the stalks into small rolls.
Whip the sour cream and 20 g mustard with the whisk of the hand mixer until creamy. Stir in approx. 2/3 chives and apple, except for some for garnishing, and season to taste with salt and pepper. Add the remaining mustard in streaks and arrange in a bowl.
Sprinkle with the remaining apple cubes and chives.