Chicken Sliders with Spicy BBQ Mayo

Name: Chicken Sliders with Spicy BBQ Mayo
Ingredients: Canola oil; 1 medium onion, chopped; 1 tablespoon chopped garlic; 2 pounds bone-in, skin-on chicken thighs, about 8; 1 sprig fresh thyme; 1 sprig fresh rosemary; Kosher salt and freshly ground black pepper; 1/2 cup water; 2 teaspoons sugar; 1 tablespoon apple cider vinegar; 1/2 teaspoon red pepper flakes; 1 head green cabbage; 1/2 cup mayonnaise; 1/2 cup barbecue sauce; 1 tablespoon spicy brown mustard; 1 tablespoon hot sauce; 1 dozen small dinner rolls, sliced