First of all, look and see what you have already got in the cupboards, fridge and freezer. Plan as many meals as you can using what you already have.
Buy rice, pasta, and potatoes, a big bag of lentils, bag of chick peas, bag split peas, bag of kidney beans, tinned tuna and pilchards, tinned tomatoes, frozen mixed veg, corn and peas, milk, flour, eggs, baked beans, cheese, marg, porridge, apples, bananas, onions, stock cubes.
You could make things like;
lentil stew
lentil curry
lentil chilli
sheperdess pie with frozen veg
tomato cheese rice
tomato pasta
tuna pasta made with cheese sauce and veg
tuna and peas in white sauce over rice or on toast
pilchard loaf ( a small unsliced loaf, cut into 4 or 5 lengthways, spread with mashed pilchards in tomato sauce, topped with 1pint white sauce and baked for about 1/2hour)
lentil and tomato soup with bread
eggy rice with onions and mixed veg
Chick pea curry and rice
spicy chick peas with onion, tomatoes and lemon juice (if you have a lemon or some lemon juice)
buttered pasta with vegetables and cheese
savoury rice with veg
corn fritters
bean burgers in rolls
spicy kidney beans with toast or rice
potato and onion bake using HM white sauce and any veg you have hanging around and a couple of rashers of bacon chopped into tiny pieces if you have any.
mash with cheese and beans
spicy split pea soup
Have porridge, hm pancakes or muffins for breakfast. When you cook rice, cook twice as much as you need, keep the rest in the fridge and use it to make hot rice cereal for breakfast, rice muffins, rice salad or eggy rice. When you make mash, make extra, mix it to make a dough with flour and fry in patties to make potato cakes that you can serve with beans for breakfast or lunch. Save all leftovers, even if there is only enough to feed your littley for lunch. If you feel the need to eat meat try making mince mixed half and half with lentils. If you are concerned about omega three, replace a tin of tuna with a small tin of pink salmon.
Hope these help at all