Step 1 Drain the garbanzo beans, place them in a strainer and rinse them under cold, running water. Pat them dry with a towel. Combine the beans with 1 teaspoon minced garlic, the red pepper flakes, cumin, 1 teaspoon salt, one-fourth cup of the olive oil and the lemon juice. Stir in the grape tomatoes and set aside.
Step 2 In a small bowl, combine the remaining one-fourth cup olive oil, the remaining 1 teaspoon minced garlic and one-half teaspoon of salt.
Step 3Arrange the spot prawns in a single layer in two grilling baskets. Brush with the garlic-olive oil and grill over a medium-hot fire until bright red and slightly charred on one side, 2 1/2 to 3 minutes. Turn and cook another 2 1/2 to 3 minutes on the other side.
Step 4Stir the arugula leaves into the garbanzo bean-tomato mixture, taste and adjust seasoning. Mound the salad in the center of a platter and arrange the prawns around the salad. Serve immediately.