Combine ingredients in a large bowl; stir until well blended. Put about 1 1/3 cups of mix into three 1-pint airtight containers and label as Onion-Flavored Rice Mix. Store in a cool, dry place and use within 6 to 8 months.
Onion-Flavored Rice: Combine 1 1/3 cups Onion-Flavored Rice Mix, 2 cups cold water, and 1 T butter or margarine in a medium saucepan. Bring to a boil over high heat; cover and reduce heat. Cook for 15 to 25 minutes, until liquid is absorbed.