Pour water and oats into a rice cooker. Seal and select setting according to manufacturer's instructions; cook until tender, about 15 minutes. Pull out the pot as soon as the unit clocks to Warm setting. Set aside.

Heat oil over high heat in a large frying pan. Add chicken and cook, covered, for 4 minutes, stirring every minute. Add green beans and cook, covered, stirring every minute, for 4 minutes. Pour in aminos and stir; chop mixture using a spatula. Cover, reduce heat to low, and let simmer for 10 minutes.

Add cooked oatmeal to mixture; stir and chop further using a spatula. Remove from heat and let cool completely, 20 to 30 minutes.

Package for freezing.