Rinse the salmon with cold water, pat dry and season with 2 tablespoons of lemon juice, salt and pepper. Turn in the flour and brush on all sides with 4 tablespoons of seasoned mustard.
Wash, peel and roughly grate the potatoes. Bread the salmon fillets in it. Press the grated potato lightly. Fry the fish over medium heat in 2 tablespoons of hot oil for 5 minutes on each side. Then carefully turn once.
Peel the garlic. Mix with yoghurt, milk, 4 tablespoons of seasoned mustard, 1 tablespoon each of oil and lemon juice, beat with a hand blender and season with salt and pepper. Serve as a cold sauce with the salmon fillets.