In 12-inch nonstick skillet, add milk, hot water and sauce mix (from Hamburger Helper™ box); stir to combine. Stir in uncooked pasta (from Hamburger Helper™ box), sweet potato, diced cooked chicken and pepper.
Heat to boiling, stirring occasionally. Reduce heat; cover and simmer 9 to 11 minutes, stirring occasionally, until pasta is tender and sauce is thick. Remove from heat.