Clean, wash and drain the salad. Cut lettuce into bite-sized pieces, cut radicchio into thin strips, removing the stalk. Peel the onions. Dice bacon and onions and fry in oil at medium heat for 8 minutes.
Add vinegar, salt and pepper to the pan and mix with the fried ingredients, allow to cool. Remove the crusts from the bread, dice it and fry it in the fat while turning it golden brown. Arrange the radicchio and lettuce on 4 plates, pour the salad dressing over it and sprinkle with the bread cubes.