Heat oil in a small nonstick skillet over medium heat. Add curry paste, ginger and garlic. Cook, stirring constantly, until fragrant, about 2 minutes.
Combine broth, peanut butter, vinegar, tamari (or soy sauce) in a food processor or mini food processor. Add the curry mixture and process until smooth, about 20 seconds.
To make ahead: Refrigerate for up to 2 days.
Tip: People with celiac disease or gluten sensitivity should use soy sauces that are labeled "gluten-free," as soy sauce may contain wheat or other gluten-containing ingredients.