Rinse and trim chicken. Cut into bite-size pieces and lightly season with salt and pepper. Cook chicken in a large skillet over medium heat until no longer pink, about 10 minutes. Remove from heat and let cool.
While chicken cools, melt butter in a large saucepan over medium heat. Add onions. Cook and stir until soft, about 5 minutes. Add curry powder, ginger, garlic, sugar, bouillon, and salt; cook and stir for 2 minutes. Add flour; cook and stir for 2 minutes. Mixture should be a thick paste. Gradually add the water and milk; cook, stirring constantly, until the sauce has thickened. Once thickened, whisk in lemon juice. Let sauce cool.
Spread sauce evenly over the chicken. Seal and freeze flat.
Prepare after Freezing:
Completely thaw one entree in the refrigerator. In a large skillet over medium heat, bring the chicken curry to a simmer and cook until heated through. Do not boil. Serve over rice and with toppings, if desired.
I like to double the recipe, eat some for dinner, then freeze the leftovers.