It takes 1300 square meters to feed a vegan for 365 days, it might take more than twice for meat eaters. So the vegan option is better if you want to save space.
For one single day, we get 3,5 square meters, a really small garden is enough to feed a human for one day for 3 meals. It gets down to less than 1.18 meters for one single meal.
But what about efficiency? Hydroponics and vertical farms exist, which means you could make the walls of a house to be a living garden. Or build an enormous garden on top of each persons roof.
Vertical farms can yeld up to 20 times more crops per square meter, therefore a small sleeping room of 12 square meters might be enough to feed a person for 207 meals, roughly 69 days.
This is all approximation since different crops have different nutritional values, but if you wanted to be really efficient. I suggest soy.
Soy beans are the highest proteic food on the entire planet and rich in fat. 36% of soy is pure protein by weight, more than any meat and it's close to protein powders.
This is what a hydroponic vertical farm of soybeans looks like,and remember soy is objectively speaking the most nutrious food on the planet by sheer numbers alone
Together, protein and soybean oil content account for 56% of dry soybeans by weight (36% protein and 20% fat, table). The remainder consists of 30% carbohydrates, 9% water and 5% ash (table). Soybeans comprise approximately 8% seed coat or hull, 90% cotyledons and 2% hypocotyl axis or germ -source
Soy can be cooked in many different ways.
Soy mince with tomato sauce, resembling an Italian ragu.
As plain cooked beans or chilly
It can be made into a paste and make tofu grilled, roasted, fried, boiled or even raw
it can also be used to make bean stews.
it can be used to make cooking oil
it can be used to make sweets
it can be roasted and eaten like peanuts
Soy beans alone have been a staple food sources for many Asian cultures for millennia.
- garlic grows in agglomerations, it doesn't care about space as long has it has enough water and light, you could get one garlic bulb for every 1.5 centimetres of space, which is the average diameter of a garlic bulb
Peppers/tomatoes grow vertically but can also be compressed into small spaces
And produce up to 60 fruits per plant if fertile source a single plant can be grown 40 centimetres apart source but can be scaffolded as shown in the images above.
onions, they grow just like garlic but being bigger require more spacing apart, you could grow one every 11 centimetres based on their diameter
tumeric, sugar and other tubers are like growing potatoes, you can get a dozen or more tubers from one single plant. And it requires little space.
For a single meal option with diverse foods and spices, 1.18 square meter might still be enough.
If meat must be an obligatory option then the most economic choice both in therms of space and feed are insects,rats or small lizards as they are really small and can feed themselves by eating smaller organism or things like paper/clothes or hairs.
Filther feeding fish might be an option too, but they require some water source.
Does finding a small animal in your home and cooking it count as growing it?