For the waffles with salmon and dill sauce, first prepare the dill sauce. For this, finely chop the dill and stir with the other ingredients until smooth. Refrigerate until ready to use.
Sift together buckwheat flour, wheat flour, baking powder and baking soda. Stir in salt and sugar.
Melt butter and let cool a little. Mix with eggs and buttermilk and add to flour mixture.
Heat the waffle iron according to instructions and pour in some batter. Flip waffle iron closed and bake waffle as crispy as desired. Remove and do the same with the remaining batter.
Spoon a tablespoonful of sauce on each waffle and drape a slice of salmon on top. Serve waffles with salmon and dill sauce.