I did RUE that heirloom variety I got from Baker Creek, but now I'm thankful for that too-hot-to-eat radish because it has forced me to look outside the radish as a garnish rose (not that I've made a radish rose since I was 16 or so.)
My first try was to roast them, following a recipe that promised to take away the bitterness, making the pretty, red root taste just like a potato. No go! The radish top soup I made was very good, even scoring a hit with my husband, but it doesn't use the root. I then braised the roots with a bit of sugar. The braised radishes were yummy with no hint of bitterness, but I'm not a big fan of a sugared vegetable with my meal.
Next I found an easy recipe for pickling. This one was attractive because I had all the ingredients on hand, garlic cloves, whole black peppercorns, white vinegar, kosher salt and sugar. I found a plastic lid to fit a glass jar from my stash and assembled the ingredients, tossed in my clean, fresh-picked radishes, tucked them in the refrigerator and gave them a shake a few times over the next three days.
The vinegar bleaches the radish, and the radish skin's pigment stains the vinegar, so the solution is red, and the radishes turn pink throughout. It's strikingly pretty! I ate one last night with my fresh, chopped tomato, and it was terrific! The radish provided crunch and a tang of vinegar. There's no hint of the bitterness. Add a dash of olive oil for instant salad dressing.
This is one radish recipe I definitely chalk up into the success column. I will make more of these as long as the radishes keep coming, and I look forward to trying variations on the theme. Red wine vinegar, perhaps?