Preheat the oven to 180 degrees (convection oven: 160 degrees /gas oven: level 3).
Season the saddle of veal with pepper and salt. Brown the meat in hot olive oil on both sides. Steam in preheated oven for about 10 minutes. Remove from oven and quench.
Separate one lemon from the peel with a kitchen knife so that no white skin is visible and cut into very thin slices. Squeeze the juice from the other lemon.
Whisk egg yolks with mustard. With a whisk, add sunflower oil and olive oil until you have a firm mayo. Season with salt, a dash of cayenne pepper and juice of one lemon.
Add veal broth, tuna, capers and caper juice to hand mixer with mayo and mix thoroughly. Add salt, pepper and a little bit of lemon juice to taste.
Chop the meat into narrow slices and offer on plates in a fan shape. Sprinkle with coarse sea salt and pour a little tuna sauce on top. Offer the rest of the sauce in a dessert dish for this. Garnish with lemon slices and a few capers. Serve with baguette and a green leaf salad.