Cook the pasta according to package directions. Drain and set aside.
While the pasta is cooking, heat the oil in a large saucepan or Dutch oven over medium-high heat. Add the onion and sauté for 2 minutes, stirring frequently. Add the peppers and cook an additional 2 minutes.
In a small bowl, whisk together the broth, flour, peanut sauce, and salt until well blended. Add the broth mixture to the peppers and onion and bring to a simmer, stirring constantly. Reduce the heat and continue to simmer and stir gently until the mixture thickens, about 2 minutes. Add the pasta and shrimp and heat through. Place in individual bowls, top with peanuts, and serve.
