While preparing your ingredients, get the corn cooking first since it requires the most time. Boil the corn in salted water for 8-10 minutes until tender, then remove and let cool slightly before cutting the kernels off the cob. While the corn cooks, dice your avocados into ½-inch cubes, finely dice the red onion, halve or quarter the cherry tomatoes, and chop your cilantro. Preheat your grill to medium-high heat and prepare your 4 skewers.
In a small bowl, whisk together the mayonnaise, sriracha, and 2 tablespoons of lime juice to create the spicy mayo—this can be made while other components cook. In another bowl, combine the cooled corn kernels from Step 1 with the diced avocado, cilantro, red onion, 2 tablespoons lime juice, 2½ tablespoons olive oil, salt, pepper, and queso fresco. I like to gently toss the corn salad to keep the avocado from getting too broken up, which keeps the presentation looking fresh. Set both bowls aside until ready to serve.
Pat the shrimp dry with paper towels to remove excess moisture, which helps them grill better and get a better char. Thread the shrimp onto your 4 skewers, dividing them evenly—about 8-10 shrimp per skewer depending on size. In a small bowl, combine the 2 tablespoons vegetable oil with 1¼ teaspoons salt and 1 teaspoon smoked paprika. Coat the skewered shrimp generously on all sides with this seasoned oil mixture.
Place the seasoned shrimp skewers on your preheated grill and cook for 2 minutes without moving them to develop a nice char. Flip the skewers and immediately brush the cooked side with barbecue sauce. Grill for another 1-2 minutes, then flip again, brush the second side with barbecue sauce, and grill for a final 1-2 minutes until the shrimp are pink and cooked through. The shrimp will continue cooking slightly after they come off the grill, so don't overdo it—they cook quickly.
While the shrimp are grilling, prepare the couscous according to package directions, then fluff it gently with a fork to prevent clumping—I find this step essential for getting the right texture. Divide the fluffed couscous evenly among 4 bowls. Top each bowl with one grilled shrimp skewer, a generous portion of the corn salad from Step 2, and some of the halved cherry tomatoes.
Drizzle each bowl with a generous dollop of the spicy mayo from Step 2. Top with fresh cilantro and serve with lime wedges on the side for squeezing over the bowl. The lime juice brightens all the flavors and helps tie everything together.