Preheat oven to 450° F. Toss Brussels sprouts with olive oil and place in a single layer on a baking sheet. Depending on the size of your baking sheet, you may need more than one. Roast until tender and slightly crisp, about 25 minutes. Remove from heat and set aside.
While the sprouts are cooking, whisk together the scallions, soy sauce, rice wine vinegar, sugar, water and corn starch in a small bowl. Set aside.
Right before the sprouts are done cooking, heat a wok over medium-high heat. Add in the chilis, ½ teaspoon red pepper and black pepper and cook until fragrant and toasted, stirring often, about 2 minutes. Add in the peanuts and cook another minute until toasted. Reduce heat to medium and add in the garlic and ginger and cook another minute, taking care not to burn. Add the corn starch mixture to the wok. Cook for 4 to 5 minutes until thickened, stirring occasionally.
Add in the cooked Brussels sprouts and toss until hot and coated with the sauce. Season to taste for heat. If more is desired, add in additional ¼ teaspoon red pepper flakes.
Recipe by Alexandra Caspero, MA, RD