Meat-free cooking on a budget has a reputation for being worthy and a bit grim. It needn't be. The trick is to stop treating beans, lentils and eggs as substitutes for something else and start treating them as the main event, then build your week around whatever the British growing calendar is offering cheaply that month. Do that and you can eat very well indeed for considerably less than the price of a couple of chicken breasts.

Start with the cheap proteins

Three things do most of the heavy lifting in a thrifty meat-free kitchen: pulses, eggs, and a well-stocked spice shelf. Gram for gram, dried pulses are the cheapest protein you can buy, and tinned ones are only marginally more expensive once you factor in the gas or electricity for cooking.

• Red lentils need no soaking and collapse into a sauce in twenty minutes. A 500g bag gives you roughly six generous portions and costs a couple of pounds.
• Tinned chickpeas and beans are your convenience food. Buy the plain ones rather than the ones in sauces, which are mostly water and sugar.
• Split peas and barley bulk out soups and stews for pennies and give a lovely thick texture.
• Eggs are the fastest dinner in the house — a frittata, a shakshuka, or a couple of eggs poached on top of leftover lentils.
• Frozen peas and broad beans are picked and frozen within hours, so they're often better than tired fresh ones and never waste.

A useful rule of thumb: aim for about 80g of dried pulses or a 400g tin between two people. That's a proper portion, not a token scattering.

Eat with the seasons, not the supermarket

Imported vegetables are expensive because they've travelled. British ones are cheap in the weeks when there's a glut. If you plan around what's actually growing here, your shopping bill drops without you doing anything clever.

• January to March: leeks, parsnips, swede, carrots, January King cabbage, kale, and forced rhubarb. This is root-vegetable season — roast them hard with oil and cumin and serve with lentils.
• April to June: spring greens, spinach, salad leaves, fresh peas, broad beans and asparagus. Light, quick cooking; eggs and new potatoes do the rest.
• July to September: courgettes, runner beans, tomatoes, sweetcorn and beetroot. Make the most of tomatoes while they're cheap and full of flavour.
• October to December: squash, celeriac, sprouts, red cabbage, Jerusalem artichokes and the roots again. Stews, traybakes and mash weather.

If you grow anything at all, this list doubles as a sowing guide. If you don't, a local veg box or a market stall at closing time will usually beat the supermarket on price for whatever is in season that week.

Map out the week before you shop

The single biggest saving is planning. Seven separate recipes means seven sets of ingredients, half of which go limp. Instead, pick four or five flexible templates and rotate them so the same vegetables and pulses get used across several meals.

• Lentil and root-veg traybake — roast a tray of whatever roots and onions you have, stir through cooked lentils, finish with a sharp dressing.
• Bean stew or curry — one tin of beans, one tin of tomatoes, onion, spice, and whatever greens need using up.
• Soup plus something baked — a pot of split pea or leek and potato soup with soda bread or a cheese scone is a full dinner for very little.
• Egg dish — frittata, omelette or shakshuka, using up the odds and ends in the fridge.
• Pasta or grains with pulses — pasta e ceci, or pearl barley cooked like a risotto with peas and lemon.

Cook once, eat twice. Doubling a stew costs almost nothing extra and gives you lunch or a second dinner for free.

What a week might actually look like

• Monday: leek and potato soup with cheese scones.
• Tuesday: red lentil dhal with rice, spinach stirred in at the end.
• Wednesday: roast carrot, parsnip and onion traybake with a tin of chickpeas and a lemon-tahini dressing.
• Thursday: leftover dhal, or a frittata with anything left in the veg drawer.
• Friday: pasta e ceci with rosemary and a handful of frozen peas.
• Saturday: black bean chilli with rice, soured cream and whatever salad leaves you've grown.
• Sunday: a proper bake — nut roast, a big vegetable pie, or a squash and chickpea tagine with couscous.

Written down like that, the shopping list is short: onions, carrots, leeks, potatoes, a couple of cabbages or bags of greens, tinned tomatoes, a few tins of pulses, dried lentils, rice, pasta, eggs, cheese. Fewer than twenty items, and most of them keep for weeks.

Grow the bits that cost the most

Kitchen gardening pays best when you grow things that are expensive or perishable to buy. Salad leaves are a prime example: a supermarket bag costs more than a packet of seed. Sow a small tray of cut-and-comme-again lettuce, rocket or mustard every fortnight on a windowsill or in a pot by the back door, and you'll have leaves from March to October.

• Herbs: parsley, coriander, mint and chives in pots. Fresh herbs lift a cheap bean dish more than any other single thing.
• Chard and kale: cut-and-come-again, cropping right through the winter and standing up to frost.
• Runner and broad beans: heavy croppers, and the surplus freezes beautifully.
• Tomatoes and courgettes: greedy plants, but two or three of each will keep you in summer suppers.

Small habits that keep the costs down

• Cook dried beans in a big batch and freeze them in tin-sized portions.
• Keep vegetable trimmings — onion skins, carrot tops, celery ends — in a bag in the freezer for stock.
• Toast and grind your own spices; whole spices are cheaper and last for years.
• Use the whole vegetable: cauliflower leaves, beetroot tops, broccoli stalks. All edible, all good.
• Stale bread becomes croutons, breadcrumbs or a baked pudding — never the bin.
• Season boldly. A cheap dinner tastes luxurious with proper salt, acid and heat.

None of this is about going without. It's about cooking with the grain of the British year, leaning on pulses and eggs, and letting a well-planned week do the work for you.