Brussels Sprout Salad with Red Onion and Pecorino

From Not Without Salt.
Ingredients:
1/2 small red onion, thinly sliced
Juice of 1 lemon
1 tsp. honey
1 tsp. whole grain mustard
Salt
Freshly ground pepper
1 Tbsp. olive oil
3 c. Brussels sprouts (use larger sprouts if possible)
1/2 c. finely grated pecorino romano

In a small bowl, whisk together the lemon juice, honey, mustard and a pinch of salt and pepper. Whisk in the olive oil until the dressing is emulsified. Add the sliced onions and set aside.
Trim all of the brussels sprouts, cutting off any bruised outer leaves and slicing off a good portion of the hard root end. Using a mandoline, shave the sprouts one at a time. When you’re done, use your fingers to gently separate the leaves so that the shredded sprouts resemble a very fine slaw.
Put the sprouts in a serving bowl and toss gently with the onions and the dressing. Fold in the pecorino, taste and adjust seasonings if necessary. Finish with a bit more pecorino on top then serve immediately.
Serves 6.