Cut your 2 lbs chicken breast into bite-sized chunks and season generously with salt and pepper. Heat a large skillet over medium-high heat and sear the chicken for about 6-8 minutes until the outside gets golden brown and it's cooked through. You'll know it's done when there's no pink inside and it reaches 165°F internally.

In a separate bowl, combine your mayonnaise, sweet pickle relish, and Dijon mustard together. Stir it smooth and set it aside—this is your flavor base that ties everything together. Don't skip tasting it now; adjust the mustard if you want more kick.

Melt 1/2 cup butter in another skillet and add your grilled corn kernels plus the diced red bell pepper. Cook for about 3-4 minutes on medium heat, stirring occasionally until the pepper softens slightly and everything gets warm. The butter should coat everything beautifully.

In a large mixing bowl, combine the cooked chicken, mayo mixture, cooked elbow macaroni, and that corn-pepper mixture. Fold everything together gently—I use a wooden spoon instead of a whisk to keep things from getting over-mixed. This is where I add my fresh cilantro for that summery pop.

Stir in your 1 cup cooked ground beef and fold one more time to distribute it evenly throughout. Here's my trick: taste it now and adjust seasoning if needed—sometimes this needs a pinch more salt depending on what else you're serving. Trust your palate over the recipe.

Transfer everything to a baking dish and sprinkle your shredded cheddar cheese evenly across the top. Then add your breadcrumbs mixed with a little extra melted butter (about 2 tablespoons) to create that golden topping. This step makes it look fancy without being complicated.

Bake at 350°F for 20-25 minutes until the cheese melts completely and the breadcrumb topping turns golden brown. Don't leave it in the oven unattended—mine once caught too much color on one side because I got distracted. Let it cool for 5 minutes before serving so it holds together nicely.