In a small saucepan combine lentils and 1-1/2 cups water. Bring water to boiling over high heat. Reduce heat and simmer, covered, about 25 minutes or until tender. Drain, reserving cooking liquid.
Meanwhile, cook rice according to package directions.
Puree lentils and rice using a blender or food processor, adding desired amount of reserved cooking liquid. Use within 1 day, or freeze up to 1 month.
Spoon finished food into ice cube trays. Cover with waxed paper and freeze until firm. When ice cubes are frozen, remove cubes from tray and store in a resealable plastic freezer bag or freezer container. Label package with contents and date. Use within 1 month. Before serving, let thaw in the refrigerator overnight.
Heat thawed mixture to lukewarm in a small dish set in a pan of hot water. Stir before serving. Always sample a small bite to make sure the food is not too hot.