I don't eat butter because I love cows, calves, and the planet. A good quality organic margarine works almost as well. Ok, not quite as well, but almost as well. Think of the calves. And make up for any loss of flavour with really good salt. You can afford to splash out because the huge bunch of radishes only set you back €1 at the market.
Fleur de sel is a fancy coarse sea salt which is harvested by hand, and produced mainly along France's west coast (Brittany and below).
There's something special about the peppery crispness of radishes, smooth mouth-feel of butter/margarine, and salty bite of... salt. Even my mean cat approves.
Radis, beurre, sel, chat.