Cook the linguine or fettuccine noodles al dente according to package instructions.

Drain the noodles well and transfer them to a large bowl.

In a small bowl, whisk together the peanut butter, water, soy sauce, sesame oil, and rice vinegar until smooth.

Pour the sauce over the noodles and mix thoroughly to combine.

Add the thinly sliced carrots and green onions to the noodles.

Mix the vegetables into the noodle mixture.

Garnish with sesame seeds and peanuts (optional).

Serve immediately or at room temperature.