DRESSING:

3 tbsp. fresh lime juice
1 1/2 tbsp. fresh lemon juice
3/4 tsp. cumin
3/4 tsp. chili powder
3/4 tsp. salt
1/2 c. vegetable oil

In a bowl, whisk together the lime, lemon, cumin, chili powder and salt. Add the oil in a stream, whisking and whisk until emulsified.

SALAD:

1 lb. cooked black beans
1 1/2 c. chopped, seeded tomato
1/3 c. minced fresh coriander plus coriander sprigs for garnish
1 1/2 c. thawed frozen corn kernels
3/4 c. thinly sliced scallion

Combine all of the ingredients in a large bowl and toss with the dressing. may be made one day in advance. Garnish with fresh coriander just before serving. Serve slightly chilled or at room temperature.