Black Bean Shrimp Salad with Corn & Pickled Onions

Bahan-bahan (4 porsi)

• ¾ cup distilled white vinegar
• 3 tablespoons sugar
• 1/8 teaspoon salt
• 1 medium red onion, (thinly sliced)
• 2 ears fresh corn
• 2 (15-oz) cans black beans, best quality such as Bush's or Goya, drained and finsed
• 3 scallions, (white and green parts, thinly sliced)
• 1/3 cup chopped fresh cilantro, (plus more for serving)
• ½ cup extra-virgin olive oil, (divided)
• 2 tablespoons fresh lime juice, (from 1 lime)
• 2 tablespoons fresh lemon juice, (from 1 lemon)
• ¾ teaspoon salt, (divided)
• ½ teaspoon ground cumin
• 1 pound medium shrimp, (peeled and deveined, thawed if frozen)
• 4 cloves garlic, (finely chopped)
• 4 oz feta cheese, (crumbled)
• Freshly ground black pepper, (for serving)