If you mean from having completely bare cupboard then
Rice or pasta ( you don't need both at once)
Onions
Veg oil
Potatoes
Flour ( If you can bake )
Tinned tomatoes
Basics herbs and spices pepper, chilli, basil, Italian seasoning, garlic , ginger, curry powder
Marg / butter
Stock cubes
Peppers
From the above you could make a basic but ok meal
Then add one from each group
Pulses -
lentils, chick peas , cous cous, bulger wheat kidney beans , baked beans
Vitamins / iron -
kale, spinach , broccoli, carrots, spring green cabbage,
Veg -
Mushrooms , courgettes, bean sprouts, lettuce, cucumber ,.green beans , corn , peas , Chinese leaves , cabbage
Protein-
Chicken ( thighs are gen best value / taste )
Cooking bacon , stewing steak , fish tinned or fresh, eggs , cheese, tofu,
Filling stuff
Bread , noodles, wraps, sweet potato, porridge,
Sauces-
Mayo, brown, tomatoe, Worcestershire , chilli , mustard, one salad dressing.
Nice extras -
jam / marmalade / nut butter , brekfast cereal , frozen mixed friut , yoghurt, crisps.
Drinks - coffee , squash , hot chocolate or horlicks and if the budget will stretch to it a bit of booze .