Heat the cream in a saucepan, add the nougat, remove the saucepan from the heat and stir with a whisk until the nougat mass has dissolved. Chill the cream-nougat mixture for 3 hours. In the meantime, melt the couverture in a water bath, dip the 56 walnut halves halfway into the couverture and let them dry on a cake rack. Finely chop the remaining walnut kernels. Whisk the nougat mixture with the whisk of the hand mixer until a thick, creamy mixture is formed, fold in the finely chopped nuts and fill into the walnut half moulds with a teaspoon. Place one walnut on top of each, lift it out of the pallet and place it in a paper sleeve as desired