Rinse the dried black beans and cook them in a large pot of boiling water until tender, about 1 hour. Drain and set aside to cool.
In a dry skillet over medium heat, toast the cumin seeds until fragrant and slightly browned, about 1 minute. Remove from heat and finely grind the seeds or leave whole for a toasted flavor.
Place the minced garlic and half of the toasted cumin into a small bowl, then add the olive oil and lemon juice. Whisk together to create a flavorful dressing.
Chop the cherry tomatoes and red bell pepper into bite-sized pieces. Place them into a large mixing bowl.
Add the cooled beans to the bowl with vegetables, then pour over the dressing. Toss gently to coat all ingredients evenly.
Season the salad with salt and freshly ground pepper to taste. Give it one last gentle toss.
Transfer the bean salad to a serving dish or cover and refrigerate for at least 30 minutes to allow flavors to meld. Serve chilled or at room temperature.