Slice radishes into coin shapes about 1/8th inch thick coin shapes and pack into a quart sized mason jar. I like to use a mandoline slicer for this so I have consistent thickness, but you can just use a knife too.
Roughly chop garlic cloves and add them to the jar with the radishes. Try to pack them down a little.
Add vinegar, water, sugar, salt, msg, red pepper flakes and mustard powder to a small saucepan over medium high heat.
Heat vinegar mixture until it just starts to boil and then turn off the heat. Stir mixture and pour it into the jar over the radishes.
Close the jar lid and let rest on your counter until cool.
Add to fridge and enjoy some great radish pickles over the next few weeks.