Peel and roughly grate the sweet potato.
Melt the butter in a saucepan and beat the eggs until they are thick and frothy. Put sour cream in a bowl, stir in rice flour and baking powder. Salt and pepper the cream.
Mix the cream with the sweet potatoes. Finely puree the beetroot (100 gr.) With a blender. Cut the remaining beetroot (50 gr.) Into large pieces. Mix the pureed beetroot with the cream cheese, season with lemon juice, salt and pepper. Fold the beetroot pieces into the cream.
Cut the cress from the bed. Wash, peel and slice the cucumber. Heat up the waffle iron and grease with a little fat. Bake 6-8 waffles one after the other from the batter. Arrange the sweet potato waffles on plates, serve garnished with beetroot cream, cucumber, salmon and cress.