Combine the vinaigrette (below), cilantro stems, and mint in a bowl, and set aside.
Peel away any loose or discolored outer leaves, trim the dry end of the stems with a knife, and cut the sprouts in half. Cut any especially large ones in quarters. Do not wash, especially if frying the sprouts. If roasting, and you must, dry very well.
To roast the brussels sprouts (recommended): Heat the oven to 400 degrees F. Heat 2 tablespoons grapeseed oil (or just enough to evenly coat the bottom of the pan) in 2 oven-safe wide skillets (12 to 14 inches) over medium heat. When the oil slides easily from side to side of the pan, add the brussels sprouts cut side down. When the cut faces of the sprouts begin to brown, transfer the pan to the oven to finish cooking, about 15 minutes. Alternately, if you don't have 2 large skillets or are cooking more sprouts for a larger crowd, roast them in the oven: toss them with 1 tablespoon of oil per pound and spread them on a baking sheet, cut sides down. Roast in the oven, checking for browning every 10-15 minutes, tossing them around with a spatula only once they start to brown nicely.The sprouts are ready when they are tender but not soft, with nice, dark brown color.
To fry the brussels sprouts: Heat 1 1/2 inches of oil in a deep saucepan over medium-high heat until a deep-fry or instant-read thermometer registers 375°F. Line a plate with paper towels. Fry in batches that don’t crowd the pan -- be careful, these will pop and spatter. Brussels sprouts will take about 5 minutes: when the outer leaves begin to hint at going black around the edges—i.e., after the sprouts have sizzled, shrunk, popped, and browned but before they burn—remove them to a paper towel–lined plate or tray.
Serve warm or at room temperature. When ready to serve, divide the brussels sprouts among four bowls (or serve it all out of one big bowl), top with the dressing to taste and cilantro leaves, and toss once or twice to coat.
Fish Sauce Vinaigrette
Combine the fish sauce, water, vinegar, lime juice, sugar, garlic, and chiles in a jar. Taste; If too salty, add more water and/or lime juice. This vinaigrette will keep for up to a week in the refrigerator.
Genius recipes surprise us and make us rethink cooking tropes. They're handed down by luminaries of the food world and become their legacy. They get us talking and change the way we cook. And, once we've folded them into our repertoires, they make us feel pretty genius too. Watch for new Genius Recipes every Wednesday morning on our blog, dug up by Food52's Senior Editor Kristen Miglore.