Step 1Whisk ⅓ cup chili crisp, ⅓ cup tahini, 3 Tbsp. soy sauce, and 3 Tbsp. unseasoned rice vinegar in a small bowl. Set sauce aside.
Step 2Cook 12 oz. dried soba noodles in a large pot of boiling water until almost cooked, about 2 minutes. Add 1 bunch asparagus, trimmed, cut into 2" pieces; cook until noodles are al dente and asparagus is crisp-tender, about 1 minute. Drain, reserving 1 cup cooking liquid. Rinse noodles and asparagus under cool running water; reserve pot.
Step 3Heat 2 Tbsp. vegetable oil in a medium skillet over medium-high. Cook 1 lb. ground pork in an even layer, undisturbed, until browned, about 5 minutes. Continue to cook, stirring and breaking up with a wooden spoon, until cooked through, about 3 minutes. Add reserved sauce and cook, scraping up browned bits, 1 minute.
Step 4Transfer pork mixture, noodles, and asparagus to reserved pot. Add ⅔ cup cooking liquid; cook over medium heat, stirring gently with spoon and adding more cooking liquid if needed, until noodles and meat are well coated, about 2 minutes.
Step 5Serve pork and asparagus soba topped with thinly sliced scallion tops and toasted sesame seeds.
