Steakhouse Salad with Red Chile Dressing and Peanuts

Name: Steakhouse Salad with Red Chile Dressing and Peanuts
Ingredients: 2 garlic cloves, finely grated; ⅓ cup unseasoned rice vinegar; 3 tablespoons mirin; 2 tablespoons gochujang (Korean hot pepper paste); 2 tablespoons soy sauce; ½ cup plus 2 tablespoons olive oil; plus more for grilling; Kosher salt and freshly ground black pepper; 1–1½ pound flank steak; 8 ounces sugar snap peas; ¼ cup raw peanuts; 1 teaspoon gochugaru (Korean red pepper powder); 1 head of butter lettuce, leaves separated; 2 Persian cucumbers, sliced ⅛-inch thick; 2 ounces radishes, thinly sliced; 2 scallions, thinly sliced