How to Make It
In a blender or food processor, combine the garlic, soy sauce, peanut butter, chicken broth, lime juice, red-pepper flakes, and 1/2 teaspoon of the salt. Puree until smooth.
In a large pot of boiling, salted water, cook the linguine until almost done, about 9 minutes. Stir in the snow peas and bean sprouts and cook until the vegetables and pasta are just done, about 3 minutes more. Drain and toss with the peanut sauce, the remaining 1/4 teaspoon salt, the scallions, cucumber, and 1/3 cup of the peanuts. Serve with the remaining peanuts sprinkled over the top.
Though they're certainly edible, the seeds from a mature cucumber can be somewhat watery. You can simply scoop them out of a halved cucumber with a spoon and discard them—or buy an English (hothouse) cucumber, which is almost completely seedless.