Peel and finely dice the shallot. Finely dice the matie filets and gherkins. Wash, quarter, core and dice the apple and immediately mix with 1 tbsp. lemon juice. Mix the diced matjes, apple, gherkins and onion with the mayonnaise and season to taste with salt and pepper.
Chill for 10 minutes.
Beat the gherkin stock, remaining lemon juice, salt, pepper, sugar and the oil together. Cut the cress from the bed, mix in and serve with the matie tartare. Tip: Wholemeal bread goes well with this.