In a blender or food processor, combine the toasted sesame oil, soy sauce, peanut butter, lemon juice, brown sugar, ginger, garlic, and chili garlic sauce.
Blend until completely smooth.
Set the sauce aside.
Bring a large pot of salted water to a boil.
Cook the linguine according to package directions until al dente.
Drain the pasta in a colander and let it cool for about 20 minutes, tossing occasionally to prevent it from sticking together.
Transfer the cooled pasta to a large mixing bowl.
Add the sliced celery stalks, chopped celery leaves, half of the chopped peanuts, and about ½ cup of the peanut sauce.
Toss everything together until well combined.
Garnish with the remaining peanuts and the whole celery leaves.
Serve at room temperature, with extra sauce on the side for drizzling.
Don't discard the celery leaves! They have a wonderful, concentrated celery flavor that's more herbaceous than the stalks, similar to parsley. They add a fresh, bright note to the salad.
