In a small sauce pan over medium heat, combine soy sauce (or tamari), pineapple juice, maple syrup (or agave nectar), rice vinegar, sesame oil, minced garlic, grated ginger, and onion powder. Whisk all the ingredients together until well combined and bring to a simmer.
½ cup low-sodium soy sauce, 3 tablespoons pineapple juice, 2 tablespoons maple syrup, 2 tablespoons rice vinegar, 1 tablespoon sesame oil, 2 cloves garlic, 1 teaspoon ginger, ½ teaspoon onion powder