Buy a crockpot.
Then only eat Chicken Breast, potatoes, and spinach for lunch and dinner.
For breakfast, make a smoothie that consist of oatmeal, protein, and your choice of fruit/vegetables. You can also add some boiled eggs on the side if you want.
rice and eggs w some spices for lunch and dinner, oatmeal for breakfast
plus vitamins n supplements like fish oil n s***
r/eatcheapandhealthy is a good starting point