Preheat the oven to 425 degrees F and line a large baking sheet with aluminum foil. In a large bowl, toss the brussels sprouts with 3 tablespoons of the oil and then spread in a single layer on the baking sheet. Sprinkle liberally with salt and pepper. Roast for 25 minutes, stirring halfway through, until the brussels’ are caramelized and tender but toothsome.
While the sprouts are roasting, prepare the sauce. Whisk the cornstarch with 1 tablespoon water to create a slurry; set aside. In a medium saucepan, heat the remaining tablespoon olive oil over medium-high heat. Add the garlic and cook until golden and fragrant, 2-3 minutes. Add the sambal and cook, stirring, for an additional 2 minutes. Whisk in the soy sauce, water, vinegar, and sugar. Add the chiles and turn the heat to high. Once the sauce reaches a boil, whisk in the cornstarch slurry and continue cooking, whisking frequently, until the sauce has thickened and coats the back of a spoon.
Toss the sauce with the roasted brussels sprouts and peanuts.
Serve hot.
Notes
Sambal oelek can be found in the international aisle of many grocery stores. Dried chiles de árbol can be found in the spice section of grocery stores, spice shops, and are also available online (I purchased them through Amazon).Recipe lightly adapted from Bon Appetit