Bring a medium pot of water to a boil, and cook the green beans until bright green, but still crisp, about 2 minutes. Drain the green beans into a colander and run under cold water to stop them from cooking.
Place the cooked green beans in a large bowl and add the garbanzo beans, the kidney beans, the grape tomatoes, the garlic, the shallot and the jalapeño. Toss until combined. Stir in the vinegar, mayonnaise, dill, cumin and cayenne. Adjust seasonings and add salt and pepper to taste.
Chill covered for 4 hours. Serve cold.
Three-bean salad with dill dressing | www.homesicktexan.com