Sweet herbs encompass most soft herbs as opposed to the hard herbs like rosemary, thyme and sage. You could draw on any or all of mint, parsley, coriander, dill, oregano, basil and tarragon. If you have leanings to one, two or three of these guys, grab a small bunch of each and blitz them with a splash of oil in your food processor. If you’re making mayo, to ensure the flavour is big and rounded in the finished sauce, bang the blitzed herbs into the mayo right at the beginning, when you add the mustard and vinegar.