Roughly chop the radish root and greens, garlic cloves, and parsley. Add to a high speed blender with the rest of the ingredients: Olive oil, red wine vinegar, garlic cloves, oregano, red pepper flakes, and salt and pepper.
Blend on high speed for 1 minute until a thick sauce forms. Add 1 tablespoon of water at a time if the sauce is too thick or if the blender seizes up.
When blended, pour into a ramekin or small bowl and garnish with extra red pepper flakes. Enjoy!