Heat a skillet over medium heat. Add the bite-sized chicken pieces and cook, stirring occasionally, until browned and cooked through, about 4 to 5 minutes.
Add the 1/2 cup diced red bell peppers, the noodles and seasoning packet from the VELVEETA Cheesy Skillets "Nacho Supreme" box, and 2 cups water. Stir to combine.
Bring the mixture to a gentle boil. Reduce heat to low, cover, and simmer, stirring occasionally, until the noodles are tender, about 9 to 11 minutes.
Uncover and add the Liquid Gold and the salsa packet from the box. Stir until the sauce is smooth and heated through, about 1 to 2 minutes.
Remove the skillet from heat. Top with 1/2 cup sour cream, 1 cup diced tomatoes, 1/4 cup diced green onions, and crushed corn tortilla chips, if using.
Serve immediately.