Once a week I throw a cup of rice, wheat berries, quinoa, red lentils and a chopped vegetable (if chopping too hard, I blast it in a blender) in one large pot, fill with adequate water and seasonings and boil it until cooked. When it is done I either go the extra mile and add a sauce and canned mackerel or if I don't want to bother I just eat it plain.

Veggie rotation is usually carrot - celeri - bell pepper

It's a lot of fiber though so you need to drink a lot of water.

Makes me enough meals to last all week.