Combine cabbage, vinegar, and 1/2 teaspoon salt in a bowl; let stand 20 minutes. Drain.
Cook veggie burgers according to package directions.
Combine yogurt, tahini, lemon juice, garlic, chili powder and cumin in a bowl. Stir in water, 1 teaspoon at a time, until sauce reaches desired consistency. Season with salt, to taste.
Spread tahini sauce over cut sides of buns; top bottom halves with patties, pickled cabbage, and top halves of buns.