Step 1 Combine 2 garlic cloves, finely grated , 1 lb. skinless, boneless chicken breasts, cut into bite-size pieces , 1 Tbsp. cornstarch , and ½ tsp. Diamond Crystal or ¼ tsp. Morton kosher salt in a medium bowl; season with freshly ground pepper . Toss until chicken is coated (your hands work best here). Set chicken aside. Step 2 Whisk together 3 Tbsp. gochujang (Korean hot pepper paste) , 1 Tbsp. mirin , 1 Tbsp. seasoned rice vinegar , 1 Tbsp. soy sauce , 1 Tbsp. sugar , and 1 Tbsp. water in a small bowl. Set sauce aside. Step 3 Trim 5 scallions and cut into 1½" pieces; set white and pale green pieces aside. Set dark green pieces aside separately. Thinly slice remaining 1 scallion on a diagonal; set aside for serving. Step 4 Heat 1 Tbsp. vegetable oil in a large skillet over high until shimmering. Reduce heat to medium-high and add 12 oz. haricots verts or green beans, trimmed, halved crosswise , and reserved white and pale green scallion pieces.…