In 12-inch nonstick skillet, cook beef over medium-high heat 5 to 7 minutes, stirring frequently, until brown. Add hot water and sauce mix (from Hamburger Helper™ box); stir to combine. Stir in 1 cup milk, uncooked rice (from Hamburger Helper™ box), frozen corn, green chiles and pepper flakes. Heat to boiling, stirring occasionally. Reduce heat; cover and simmer about 20 minutes, stirring frequently, until rice is tender. Remove from heat.