It's an instinctive, improvisational recipe, and I probably make it differently every time.
Begin with peanut butter (almond butter is good, too). You probably want at least 1/3 cup for each person/portion. Measure this into a bowl or plastic container (then you can store any leftover sauce in same). Add 4 Tbs tamari, 2 TBS roasted sesame oil, a dash of rice vinegar. Mix it up. Add some crushed or finely chopped garlic at this stage, if you want it. Ginger is nice too, and a few teaspoons of miso added will lower your breast cancer risk by 50% (when eaten daily). You can also add chili flakes.
Then check the texture. If it is still very thick and stiff, add a small amount of hot water, and blend until the consistency you like has arrived. Then check the taste, and adjust for balance. If it is too sharp, add a little honey or sugar.