Black Bean and Corn Salad

This is one of my favorite salads to serve with barbecued meats. It has a great mix of crunch to contrast with the beans and is a nice cool contrast to spicy barbecue sauce.

2 cups canned black beans, drained and rinsed
2 cups frozen corn
1 cup red bell_pepper ,diced
1/2 cup diced jicima
6 tablespoons fresh lime juice
6 Tbsp extra_virgin_olive_oil
1 large garlic_clove , very finely minced
1/4 cup red onion , diced
6 green_onions , tops and white part,sliced (reserve some for garnish)
1/4 cup roughly chopped cilantro (reserve a few sprigs for garnish)
1/2 teaspoons ground_cumin
1/2 tsp chili_powder
1 tsp onion_powder
1/2 cup diced tomatoes
Salt and freshly ground black pepper