1. Preheat the oil in a large saucepan on medium-high heat. While the oil is warming, cut the tempeh in half vertically, then cut each half horizontally so there are 4 thin pieces. Cut each of these pieces into 1 1/2" strips.
2. Toss tempeh in the oil cut side up to cook for about 3-4 minutes. Meanwhile, whisk all the remaining ingredients together in a saucepan over medium heat, except for 1/2 the soy sauce and the water.
3. Take the remaining soy sauce and spoon it equally over the cut side of the tempeh, and flip once the other side is golden-brown. Once both sides are browned, remove strips from pan and set aside.
4. Once the peanut sauce has become hot, mix in about 1/2 the warm water to thin the sauce, adding more to taste. Remove sauce from heat and apply liberally to the tempeh strips. Serve plain or over rice.
If any peanut sauce is leftover, another very quick meal can be made from pasta, steamed soybeans, and the leftover sauce. Simply mix them all up and enjoy!