Whisk together starch and 1 cup of water in a bowl until no lumps appear.
Fill a large pot with the remaining water and heat it up until you see tiny bubbles form at the bottom of the pot.
Right before you stir the starch mixture into the pot, whisk to combine to ensure no starch is set at the bottom of the bowl.
Slowly pour it in while stirring. Once the starch is in, turn heat to low and switch to a silicone spatula, if you haven't.
Stir the mixture gently until it turns into a semi-translucent paste, about 3-5 minutes.
Transfer to a ceramic or stainless steel bowl. Let it set at room temperature for 2-3 hours. You may place it on top of an ice bowl to speed up the process.
While waiting, make the sauce. Add minced garlic, salt and toasted sesame oil in a bowl. Then, using the back of a spoon or spatula, crush the garlic to release its flavor. Add the vinegar, soy sauce, and sugar. Mix it well and dilute it with ½ cup of water. Add more water if you prefer a lighter sauce. Refrigerate the sauce until ready to use.
Once the jelly is set, it should detach from the bowl easily. If not, gently pull the side from the bowl and invert to a plate.
Dab the jelly with water before cutting.
Use a jelly scraper or knife to cut it into your desired shapes.
Place jelly noodles in a bowl and ladle enough sauce over. Top with chile oil with its sediment, chopped greens, sesame seeds, and toasted peanuts. Serve cold.