Cut off the ends of the stems of the fiddleheads. Place them in a bowl of cold water and swirl them around to clean them thoroughly. Discard water and repeat process.
Drain the fiddleheads and steam them in a steam basket for at least 10-12 minutes, then place them in icy cold water for 1 or 2 minutes to stop the cooking process.
Drain and transfer to serving plate. Set aside.
Add all the ingredients of the dressing to your small food processor or blender and process until nice and smooth. Set aside.
Toast almonds in a small non stick pan, over medium heat, for about 2 minutes or until they take a nice golden color. Remove from heat and set aside.
Place radicchio, bell pepper, avocado, olives and almonds on top of reserved fiddleheads.
Pour vinaigrette over salad at the moment of service.