To prep the radicchio:

1. Carefully slice the radicchio in half. Remove the core and discard. Chop or tear the remaining radicchio leaves into bite-sized pieces, as desired.
2. Fill the inner-strainer of a large salad spinner (or colander) with a few handfuls of ice. Place the strainer back in the salad spinner bowl (or a bowl larger than your colander, if using) and fill with cold water directly over the ice. Allow to sit for a minute or two until chilled fully, then strain out the ice, leaving the ice-cold water behind in the bowl. It is important that all ice is removed before the radicchio gets added or you will be pulling ice cubes out for a very long time (I've done this. It's not fun).
3. Add the prepped radicchio to the ice-cold water, ensuring it is completely submerged with water. Allow to rest for about 30-minutes or more.
4. Strain the water, spin in a salad spinner (if using), and then use a clean kitchen towel to fluff dry the remaining water as best as you can.

For the candied walnuts:

1. Line a baking sheet with parchment paper or a silicone baking sheet and reserve to the side.
2. In a skillet over medium heat, add the butter, sugar, water, walnuts, and a pinch of salt. Cook for about 4 - 5 minutes, stirring regularly with a silicone spatula or wooden spoon until the butter and sugar have melted and the nuts are starting to toast slightly. Nuts can burn very quickly, so it's important to transfer them to the baking sheet the moment they have finished cooking. Using the spatula or spoon, work quickly to separate the nuts before they cool and harden. Reserve to the side to cool.

For the vinaigrette:

1. In a small mixing bowl combine the olive oil, red wine vinegar, Dijon mustard, maple syrup, 1 1/2 tsp salt, and black pepper. Whisk to combine then taste for salt and adjust if needed. Reserve to the side.

To assemble:

1. In a large mixing bowl toss the radicchio with the olives, candied walnuts, and vinaigrette. Plate the salad and sprinkle crumbled blue cheese on top, as desired.