Prepare 2 sheet pans or baking dishes lined with parchment paper.
Cut 4 of the smallest radishes into half and the other 4 into quarters. Coat with ½ tbsp of olive oil and season with salt and pepper. Place on one of the baking dishes and put into the oven for 30 minutes.
Cut the purple cauliflower into florets. Coat with 1 tbsp of olive oil and season with salt and pepper. Place on the other baking dish and put into the oven 15 minutes after the radish.
Remove both at the 30-minute mark.
In a small mixing bowl, add the rest of the olive oil, apple cider vinegar and balsamic vinegar.
Mix until well combined.
In a medium sized mixing bowl, add the watercress, dressing and salt and pepper to taste. Toss until well combined.
On a serving platter or the sheet pan you were roasting in, place the watercress as the base. Add the roasted purple cauliflower and roasted radishes on top.
Sprinkle puffed quinoa on top.
If purple cauliflower is not in season, a typical head of cauliflower will, of course, be ok to use in this recipe. Should orange cauliflower also be in season, feel free to use that instead.
You can use any coloured radishes or even a rainbow of red, white and purple to mix it up a bit. If you can find French breakfast radishes, they would look great too.
Some great watercress alternatives include rocket leaves or arugula, spinach leaves or nasturtium leaves.
If you don’t wish to use puffed quinoa, you can substitute it with puffed rice or any other puffed grain. What you’re after is some light pops of crunch but a delicate one at that.