Who doesn't like a good sandwich? And who likes a bad one? I have an uncomplicated theory about the essential difference between the two: generally, a sandwich you make yourself is very likely to be more enjoyable than one you buy. And it's always going to be more enjoyable than one you buy from the chill cabinet of a supermarket, cafe or fast food outlet. Refrigeration is truly the enemy of the sandwich. Who wants bread, butter and cheese at 3C?

But I feel we are making fewer sandwiches than we used to, even as we are buying more and more of them. We're buying out of convenience (laziness?), and failing to make because, when we buy, we are so often disappointed. So this week I'd like you to draw inspiration to get back into the sandwich game by recalling your happiest memories of Great Sandwiches You Have Made And Loved. For example, the one when you got back from a party in the small hours, found the remains of a roast chicken in the fridge, sawed a pair of doorsteps from the loaf, smacked them together with a good smear of mayonnaise, and downed the chewy-crusted, over-buttered, chicken-filled white bread with a massive cup of tea.

As you've probably heard, the sandwich is said to have been invented in the 18th century for John Montagu, fourth Earl of Sandwich. An enthusiastic and tireless gambler, he called for some roast beef between two slices of toast to be brought to the gaming table so he didn't have to interrupt a mammoth 24-hour session. Less well known is the first use of the word in print: in 1762, diarist Edward Gibbon referred in his journal to a scene at the Cocoa Tree, a chocolate house that became a gentlemen's club, where he saw a large group of aristos eating "sandwiches", thus committing the term to paper for the first time.

Logic insists that, at best, it was the coining of the phrase, not the invention of the culinary concept, that was born in this way. The gambling earl can't have been the first person to slap something sustaining between two slices of bread. (Although I'd hazard that, in fact, the wrap must have preceded the sandwich, since the flatbread clearly preceded the loaf.)

But calling a sandwich a sandwich has certainly encouraged some experimentation and customisation. From the earl to Elvis, they have been the objects of much freewheeling invention, improvisation and delight. And it's been a very international enterprise, from Lousiana's po'boy and muffaletta, to the redoubtable club sandwich, the croque monsieur of France, South Africa's bunny chow (no bunnies are harmed in the making of this sandwich – it's a hollowed out loaf filled with curry) and the Swedish smörgåstårta, which hedges its bets by placing an entire buffet between two slices of bread.

So today I'm offering a few simple ideas to help us claim back this workmanlike yet highly personal and intimate culinary pleasure. A good sandwich has to start with great bread, so buy the best you can find (or make your own). Then think about your fillings – like a great pasta sauce or pizza topping, it's usually best to go with two or at most three great ingredients, so they can really shine (one of the exceptions to this is today's pan bagnat).

And though these recipes focus on savoury concoctions, the sweet sandwich can be a delicious treat, too. The strawberry sandwich (good white bread, sliced strawberries, a sprinkling of sugar and generous smear of clotted cream) is arguably better than a cream tea, while a slightly more elaborate combination (lightly toasted slices of brioche served with sliced strawberries macerated in a little lemon or orange juice and sugar, and topped with vanilla ice-cream) is one of the easiest and tastiest summer puds I know.

Pan bagnat

This substantial sandwich's name comes from "pan-banhat", which means "wet bread" in the Provençal dialect. It's filled with many of summer's finest flavours and is the perfect thing to take on a picnic. Serves four.

1 small red onion, peeled and thinly sliced

1 round or oval country-style white loaf

3 tbsp olive oil

1 garlic clove, peeled and halved lengthways

1-2 tsp white-wine or cider vinegar

Salt and freshly ground black pepper

2 tomatoes, cut into thick slices

1 small handful black olives, stoned and roughly chopped

1 tin anchovies in olive oil, drained

2-3 hard boiled eggs, peeled and thickly sliced

6 radishes, thinly sliced

1 handful blanched, peeled broad beans (optional)

A few basil leaves, shredded

Soak the onion in iced water for 10 minutes while you prepare the rest – this will take out some of the raw sting and make it deliciously crisp.

Cut the loaf in half horizontally. Trickle some olive oil over each of the cut sides, then rub with the cut sides of the garlic cloves. Sprinkle over some vinegar and season with salt and pepper.

Drain the onion and pat dry. On the bottom half of the bread, layer the tomatoes, onion, olives, anchovies, egg, radishes, broad beans (if using) and basil. Cover with the top half of the bread. Press down a bit with your hands, then wrap tightly in foil or greaseproof paper, and leave for a couple of hours for the flavours to blend. Serve in thick slices or wedges.

Grilled spinach and emmenthal sandwich (V)

This is still a very tasty sandwich if you leave out the ham, or replace it with leftover roast chicken. Of course, if you have a panini maker, do use it, but the griddle and pan method works just as well. Serves two.

4 tbsp olive oil

2 shallots, finely sliced

1 garlic clove, minced

400g baby spinach

4 slices good white bread

200g emmenthal, grated

2 slices Parma ham

Warm half the oil in a large frying pan over a low heat and sauté the shallot for five minutes. Add the garlic and spinach, and sauté until the spinach is wilted and reduced. Leave to cool slightly, then press out excess liquid.

Heat a ridged griddle pan over moderate heat (if you don't have a griddle pan, use an ordinary frying pan). Brush the slices of bread on one side only with the remaining olive oil. Put two slices, oiled side down, on a work surface, and divide half the cheese between the two slices. Layer on the ham, followed by the spinach and the remaining cheese. Top with the remaining slices of bread, oiled side up, and press down a bit with your hands.

Place the sandwiches on the hot pan and press down with another pan for a minute. Cook for a couple of minutes a side, until the outsides are golden and the cheese is bubbling. Serve immediately.

Proper cucumber sandwiches (V)

A simple summer pleasure, but a great one when made properly. Deseeding and lightly salting the cucumber slices brings out their crunch. Serves six.

1 cucumber

Flaky sea salt

1 loaf good white bread

Unsalted butter, softened

Halve the cucumber and scrape out the seeds with a teaspoon. Slice thinly, sprinkle over some salt, then tip into a colander to drain for 30 minutes. Rinse quickly under the cold tap, and pat dry with kitchen paper or a clean tea towel.

Slice the bread and spread with a thin, even layer of butter. Arrange the cucumber slices over half the bread slices, then cover with the remaining bread, pressing down on the top a bit. Cut off the crusts, and cut into triangles or fingers.

Cheese sandwich variations

Last year, I had a cheese sandwich cook off (or should that be spread off?) with my River Cottage muckers Tim and Gill. Here's a summary of our three delightful creations.

Me Cheesey egg tartare: thinly sliced cheddar and roughly chopped hard-boiled eggs mixed with mayonnaise, chopped capers and cornichons.

Gill Grated cheddar, hot rashers of bacon, sliced avocado, mayonnaise.

Tim Thickly sliced cheddar with "quick-pickled" onions (sliced onion macerated in a little cider vinegar for 20 minutes).

Learn new skills on River Cottage's four-day cookery courses; go to rivercottage.net for details.