Rinse the tofu noodles in cold water and drain well.
Julienne the onion and bell pepper finely.
Heat olive oil in a pan and stir-fry the onion and bell pepper.
Add the tofu noodles and cook for 2-3 minutes.
In a bowl, mix peanut butter, soy sauce, oligo syrup, vinegar, and water to make the sauce.
Add the sauce to the pan, mix well with the ingredients, and stir-fry for another minute.
Transfer to a bowl and finish with black pepper and chopped scallions.