A mandoline is crucial here. (You could shave the sprouts with a knife, but they'll be less thin, less even, and more time-consuming.) Make the dressing in advance, if that works better with your schedule. Just store in the fridge and gently rewarm, to liquify, before dressing; you want it runny but not hot. —Emma Laperruque
2 to 4
chopped, toasted walnuts, divided, plus more for topping
1 1/2 teaspoons
sherry vinegar or apple cider vinegar
Shave the Brussels sprouts on a mandoline into a large bowl. Season with a big pinch of salt and toss. While that rests, make the dressing.
Put 2 tablespoons walnuts in a heatproof bowl. Add the butter to a small skillet and set on the stove over medium heat. Melt until it browns, 2 to 3 minutes. Immediately pour it over the walnuts. Leave that to cool for a moment while you combine the shallot, Dijon, vinegar, and water in a food processor or blender. Pulse to combine, scraping down as needed, until as smooth as possible. Add the walnuts and brown butter and process until smooth.
Add the dressing to the salted sprouts, plus the remaining walnuts and pecorino. Toss. Top with more nuts and cheese and some freshly ground black pepper.
Emma is a writer and recipe developer at Food52. Before this, she worked a lot of odd jobs, all at the same time. Think: stir-frying noodles "on the fly," baking dozens of pastries at 3 a.m., reviewing restaurants, and writing articles about everything from how to use leftover mashed potatoes to the history of pies in North Carolina. Now she lives in Maplewood, New Jersey with her husband and their cat, Butter. Stay tuned every Tuesday for Emma's cooking column, Big Little Recipes, all about big flavor and little ingredient lists. And see what she's up to on Instagram and Twitter at @emmalaperruque.