Whisk together all the dressing ingredients in a small bowl, and set aside.
Cook the couscous according to package instructions, substituting broth in place of water.
Fire up the grill on medium-high heat, spritz the veggies lightly with nonstick spray (or an olive oil sprayer if you have one) and grill the eggplant, zucchini, summer squash and red pepper.
You can thread the shrimp on skewers and cook them on the grill as well. Or, alternatively, you can cook them in a skillet on the stovetop over medium-high heat, with a spritz of nonstick spray.
Mix the cooked couscous, vegetables and dressing together. Top with the grilled shrimp.