Pluck iceberg lettuce into bite-sized pieces, wash well and drain. Peel the onion and cut into rings.
For the salad dressing: Mix the vinegar, elderflower syrup, maple syrup, herb salt, herb pepper and mustard together well, then beat in the rapeseed oil.
Put the lettuce in a salad bowl, pour the salad sauce over it and mix well. Finally sprinkle the onion rings over it and another two turns of herb pepper.