Grainy or smooth, slightly sweet or slightly bitter, fiercely hot or hardly hot at all: there's a mustard to pep up just about any dish

We've been getting a kick out of mustard for centuries. Roman sources describe the condiment, while medieval European royal households employed a mustardarius to ensure it was correctly prepared for table. These days, you just can't get the staff.

What you can get is ranks and ranks of different mustards: grainy or smooth, slightly sweet or slightly bitter, fiercely hot or hardly hot at all. They come in all shades of yellow and with all kinds of ingredients – cider, honey, basil, horseradish, even tea – to tempt you into a purchase. I'm tempted by some of these "cottage mustards" myself, but even when I like them – and I often don't – I'm soon back to my stalwarts, English and Dijon. (I also keep a jar of wholegrain on the go, but that's more likely to end up in a recipe than on the side of my plate.)

Hot English mustard, with that nuclear yellow glow (which comes from turmeric), seems a peculiarly English taste. Most European blends are considerably milder, but for me it's the king: hot, arresting and uniquely penetrating. I even use it on raw fish as a wasabi substitute.

I turn to Dijon, which is milder and sweeter, but still has a kick, when I want to pep up something with a more complex flavour. It cuts the tripey tang of andouillettes and I like it with cotechino, the aromatic Italian boiling sausage. But for roast beef, pork pies and cold ham, it's really got to be English.

In cooking, a dash of mustard can be a bold stroke or the most subtle of seasonings. A cheese sauce, say, is invariably improved by a pinch of English mustard powder or a spoon-tip of Dijon, but needn't taste mustardy. Many a vegetable soup – rooty or leeky concoctions especially – will be nicely lifted by a blob of the hot stuff. And I rarely make a vinaigrette that doesn't include at least a quarter-teaspoon of mustard.

When whole mustard seeds are wetted and crushed, an enzyme is activated that releases pungent sulphurous compounds. But they are ephemeral: once unlocked from the seed, they quickly evaporate. Ancient mustard-makers found they could "fix" these pungent chemicals by mixing crushed seed with an acidic liquid. Originally, that was young wine, or mustum, which gave mustard its name; these days, vinegar is the usual medium.

The volatile nature of mustard's chemical makeup is the reason dry mustard powder, once mixed with water, retains its punch only briefly – water can't "hold" that mustard flavour for long. Even jarred, vinegar-mixed mustards lose their heat over time, so keep them in a cool larder or even the fridge. Even then, if you chance upon a half-used pot, it may be better to lose it than use it. "Off" mustard won't be mouldy, but it will have lost its fire and taste sour.

For this reason, little and often is the way to buy. Those imposing 500g jars of Pommery moutarde de Meaux may look wonderful, but you need a large family of mustard addicts (and an endless supply of pork pies) to justify them.

Lapin moutarde à la crème

A fantastic way to enjoy rabbit. Serves six.

1 tbsp olive oil

250g piece salt pork, pancetta or bacon, cut into chunky cubes

2 wild rabbits, skinned and jointed

1 large onion, peeled and thickly sliced

3 large carrots, peeled and roughly chopped

4 celery sticks, roughly chopped

2 bay leaves

1 sprig fresh thyme (optional)

500ml dry or medium-dry cider

1 generous tsp honey

Sea salt and freshly ground black pepper

200ml double cream

3 tbsp grainy mustard

Heat the oil in a heavy-based frying pan. Gently fry the bacon until lightly browned, then transfer to a large casserole. Brown the rabbit in the same pan in batches, transferring to the casserole as they are done. Sweat the onion in the same pan until soft and translucent, but not coloured, and add to the casserole.

Add the carrots, celery, bay leaves and thyme (if using) to the pot. Push everything around so it's fairly tightly packed, then add the cider; top up with water, if necessary, to cover the meat, then add the honey and season. Bring to a simmer and cook at a very low, tremulous simmer for an hour and a quarter, until the meat is tender but not too flaky (older, tougher animals will take longer).

Transfer the rabbit pieces to a bowl, cover and keep warm while you make the sauce. Strain the stock – I do this first through a colander, then through muslin or a cotton cloth, to get it beautifully clear. In a clean pan, boil the strained stock hard until reduced to a scant 200ml, then whisk in the cream and mustard, and boil for a few minutes more, until thick and glossy. Taste, and adjust with salt, pepper and more mustard. Reheat the rabbit in the sauce, turning to coat the pieces. Serve with mashed potato and any spare sauce spooned over.

Celeriac and cabbage with mustard mayo

Hugh Fearnley-Whittingstall's celeriac and cabbage with mustard mayo: 'English mustard is the king.' Photograph: Colin Campbell for the Guardian

A hybrid between a classic French rémoulade and coleslaw. I serve this with meat-and-spud classics such as shepherds' pie or stew and mash. Serves four to six as a side dish.

300g celeriac

200g white cabbage

For the mustard mayo

½ clove garlic, peeled

Sea salt and freshly ground black pepper

1 tsp cider vinegar

2 large egg yolks

2 tsp English mustard

2 tsp grainy mustard

Pinch of sugar

150ml sunflower oil

100ml extra-virgin olive oil

First make the mayo. With the flat of a large knife, crush the garlic to a paste with a pinch of salt. Put in a bowl, stir in the vinegar, egg yolks and both mustards, season and add a pinch of sugar. Combine the oils in a jug, then whisk into the egg yolk mixture a few drops at a time to start with, then in small dashes, amalgamating each addition before putting in the next. (You can use an electric whisk or food processor, but you'll still have to trickle slowly and carefully, especially to begin with.) Whisk in the oil until you have a glossy, wobbly mayonnaise. Taste and add more salt, pepper, sugar, vinegar or mustard as needed. If the mayo seems very stiff, "let it down" by stirring in a little warm water.

Peel the celeriac, cut it into thin matchsticks or julienne (or coarsely grate it, if you prefer), and stir immediately into the mayonnaise, so it doesn't get a chance to brown.

Remove any damaged outer leaves from the cabbage, cut out any thick stems, then shred very thinly and stir into the mayonnaise. Taste to check the seasoning, then it's ready.

Mustardy leek gratin with almonds

Excellent beside some very simply cooked meat or fish. Serves four.

300ml whole milk

1 bay leaf

1 small onion (or 1 shallot), peeled and halved

A few black peppercorns

4 medium leeks (about 1kg in total)

Sea salt and black pepper

30g butter

25g plain flour

2 tsp Dijon mustard

About 25g flaked almonds

Put the milk in a saucepan with the bay leaf, onion and peppercorns. Bring to a simmer, turn off the heat and leave to infuse for 30 minutes.

Trim the leeks and cut them into 5-8mm slices. Heat the butter in a large ovenproof frying pan over a medium heat. Add the leeks and plenty of salt and pepper and, as soon as they start to sizzle, stir, turn the heat to low, cover and sweat for 10-15 minutes, stirring from time to time, until tender.

If the infused milk has gone cold, reheat it gently. Heat the oven to 200C/390F/gas mark 6. Stir the flour into the buttery leeks, cook gently for two to three minutes, stirring once or twice, then take it off the heat. Strain one-third of the infused milk into the leeks and stir in so the flour absorbs the liquid and there are no lumps. Repeat with the rest of the milk, adding it in one or two lots, and stirring to create a smooth, leeky béchamel sauce. Return to a low heat and cook gently for two to three minutes, stirring occasionally. Remove from the heat, stir in the mustard and season to taste.

Scatter the almonds over the creamy leeks and bake for 10 minutes, until the sauce is bubbling and the almonds are lightly toasted (check to ensure they don't burn). Serve straight away.

• Go to rivercottage.net for the latest news from River Cottage HQ. This is Hugh's last column for three months, while he takes a sabbatical.