Fry the bacon in a skillet until crisp, then remove it from the skillet to drain on a paper towel lined plate.
Add the diced radishes to the hot bacon grease in the skillet, and toss to coat in the grease. Fry on medium high heat for 10 minutes. Next, add your diced onion. Season with salt and pepper and reduce the heat to medium. You can also season it to taste with some cayenne pepper if you are wanting some spice. Cook for another 10 minutes.
Crush the bacon that you fried previously and stir it in. Remove the home fried radishes from the skillet and drain on a paper towel lined plate. Serve immediately.