Salvadorean Pupusas (Stuffed Masa Cakes)

INGREDIENTS

• 1/3 cup Hellmann's® or Best Foods® Real Mayonnaise
• 1/3 cup PLUS 1 tsp. cider vinegar, divided
• 1/4 tsp. salt
• 1 tsp. light brown sugar
• 1/4 tsp. red pepper flakes
• 1/2 small head cabbage, finely shredded
• 2 large carrots, peeled and grated
• 1 small white onion, divided
• 4 plum tomatoes (about 12 oz.)
• 1 small clove garlic, peeled
• 4 finely chopped serrano chiles, stemmed, seeded if desired
• 1 1/2 tsp. Knorr® Chicken flavor Bouillon, divided
• 5 Tbsp. oil, divided
• 1 small yellow onion, finely chopped
• 1 1/2 cups cooked no salt added red kidney beans
• 8 ounces part-skim mozzarella cheese, cut into small cubes
• 1/2 medium poblano pepper, finely chopped
• 4 cups masa harina