Heat oil in a small skillet until nearly smoking, then remove from the heat and add the peanuts. Allow to sit until lightly browned. Remove the nuts with a slotted spoon and drain, reserving the oil. Put the peanuts in a food processor or blender and blend to a rough paste. Add the chilies, ginger and garlic and continue to blend, Add the herbs and a little of the reserved oil, and continue to blend. Add the salt, sugar and lemon juice, and blend until the herbs are very finely minced. Transfer the mixture to a serving bowl and stir in the remaining oil. Serve along side warm or cold noodles, and allow each eater to spoon sauce to taste over a helping of noodles.