Brussels Sprout Tacos With Spicy Peanut Butter

Heat a small saucepan over medium. When hot, pour in 1 Tbsp. fish sauce. It should bubble up vigorously and then get thicker and slightly darker, about 30 seconds. Repeat with remaining fish sauce, incorporating 1 Tbsp. at a time. Carefully add vinegar (it may spatter), then transfer mixture to a small bowl; let cool. Stir in scallions and ginger. Taste and season with salt.

Puree red pepper and 3/4 cup whole peanuts in a food processor until a smooth butter forms, about 2 minutes. Season with kosher salt and scrape into a small bowl.

Very thinly slice one-fourth of brussels sprouts; transfer to a medium bowl. Cut remaining brussels sprouts in half. Heat oil in a medium skillet over medium-high. Shallow-fry halved brussels sprouts in batches, being careful not to overcrowd the pan, until browned and crisp, about 5 minutes per batch. Transfer to paper towels to drain, then add to sliced brussels sprouts. Drizzle with vinaigrette and toss to coat; season with kosher salt.

To serve, heat a medium skillet over medium-high. Working one at a time, cook tortillas just until warmed through; transfer to plates. Spread tortillas with some spicy peanut butter; spoon brussels sprouts over. Top with onion, avocado, chiles, cilantro, and 1/4 cup crushed peanuts; sprinkle with sea salt. Serve with lime wedges.

Vinaigrette can be made 1 week ahead. Cover and chill.