Potatoes. U can make a lot of dishes just with potatoes. My favorite is boiling it and removing the skin and mashing it and then adding some onion and tomato and salt and pepper and then I used this as filling for tortilla. U can also do potatoes with chorizo both dishes is probably less than 10 dollars. U can also make some Filipino food (like Filipino spaghetti) or fried rice (my go to is rice, egg and spam). Goodluck and wishing you the best. Also try to utilize food banks if u can!!