Heat vegetable oil in a large skillet over medium-high heat. Add chicken breasts and cook for 4 to 6 minutes per side until cooked through and golden brown. Internal temperature should reach 165 degrees F. Remove from pan and set aside to rest.

Using the same skillet, add the chopped red onion and minced jalapeño. Cook for 2 to 3 minutes, stirring often, until softened and slightly golden. Remove from heat and let cool.

Bring a large pot of salted water to a boil. Cook pasta shells one minute less than package directions. Drain and rinse under cold water until completely cool.

In a large mixing bowl, whisk together the BBQ sauce, mayonnaise, salt, and pepper until smooth.

Chop rested chicken into bite-sized pieces. Add chicken, cooked onion and jalapeño, both diced bell peppers, corn, black beans, cilantro, and cooled pasta to the bowl. Toss everything together until evenly coated. Taste and adjust seasoning before serving.