Put on pot of boiling water for pasta. Cook the fettuccine to al dente according to the package directions.
½ lb fettuccine noodles
While the pasta is cooking, whisk together orange juice, peanut butter, soy sauce, vinegar, sugar, chili sauce and lime if you are using it.
¼ cup orange juice, ¼ cup crunchy peanut butter, 2½ tbs soy sauce, 2 tbs white vinegar, 2 tbs brown sugar, ½ tsp hot chili sauce, squeeze a wedge or two of lime juice into sauce
Heat oil in skillet over med-high, once hot add the onion and garlic. Stir fry, until onion is cooked, but still has a little firmness, not mushy, then add the noodles and stir fry for 2 minutes,
1 tsp oil, ¼ cup sweet onions, 1 clove of garlic
Pour the sauce over noodles, and stir to coat, continue folding and mixing the pasta over heat for about a minute.
Serve with a splash of soy, Ponzu sauce, or wedges of lime.