Boil water and cook noodles until al dente, about 10 minutes. Reserve about a half cup of the cooking liquid. For small backpacking pots, you may need to break noodles in half first.
In a skillet on medium-high, saute garlic, ginger, and chili in the sesame oil until fragrant, about 1 minute.
Add soy sauce and peanut butter, and stir until smooth, about 1 minute. You may need up to 1/2 cup of cooking liquid if the sauce ends up too thick, so set this aside before draining noodles.
Strain noodles, and mix with the sauce. Stir in fresh cilantro and make sure noodles are fully coated in sauce. Serve hot.