Avocado Tomato Salad

Ingredients

• 1 tablespoon red wine vinegar
• juice from ½ to 1 lime
• 2 tablespoons olive oil
• ¼ small red onion
• 2 tablespoons chopped fresh cilantro
• 1 15-ounce can black beans, drained and rinsed
• 1 pint cherry tomatoes
• kernels from 2 ears fresh corn
• ¼ teaspoon salt
• 2 ripe avocados
• 1 teaspoon sugar
• salt and freshly ground black pepper
• ¼ teaspoon chili powder