Prep Radicchio: Cut radicchio head into quarters and remove the core. Separate leaves and place in a large bowl of ice water to soak for 15 minutes (to remove bitterness). Dry in a salad spinner or on paper towels.

Cut Grapefruit: Slice the top and bottom off grapefruits, then use a knife to follow the curve of the fruit to slice the peel off. Cut grapefruit into wedges.

Make dressing by whisking all dressing ingredients together. Set aside.

Assemble: Add radicchio, romaine and arugula to a bowl. Toss with desired amount of dressing. Top with grapefruit, shallots, pistachios, mint and cheese.