Marinated Black Bean Salad

1 (15 oz) can of black beans, drained and rinsed
1/2 cup chopped red onion
1/2 cup chopped celery
1/2 cup diced tomato
1 Tbsp red wine vinegar
1 Tbsp lemon juice
1 Tbsp water
2 tsp olive oil
1 tsp chopped cilantro or parsley
1 tsp cumin
1 small garlic clove, minced
1/2 tsp dijon style mustard
8 lettuce leaves (for bed)
3 Tbsp sour cream (as toppping)

Best if refrigerate for at least 2 hours.