Season the chicken chunks generously with salt and pepper. Heat olive oil and butter in a large skillet over medium heat. Once the butter melts, add the chicken and sauté until golden brown and fully cooked, about 8-10 minutes. Remove the chicken from the skillet and set aside.
Using the same skillet, add your onions, red and green peppers, and minced garlic. Sauté until the veggies are tender and the onions are translucent, about 5-7 minutes. The caramelized bits from the chicken will enhance the flavor of the veggies! Once done, set the sautéed veggies aside with the chicken.
While the veggies cook, boil the pasta in salted water according to the package instructions. Drain and set aside.
Wipe the skillet clean and whisk together mayonnaise and chicken broth in a bowl. Pour the mixture into the skillet and heat over medium, stirring constantly. The sauce will seem thin at first but will thicken as it cooks. Once the sauce is smooth and creamy, return the chicken, vegetables, and cooked pasta to the skillet. Stir everything together to coat the ingredients evenly.
Cook for a final 2-3 minutes to ensure everything is heated through. Plate up and serve immediately while hot!