Elizabeth David, one of the great sages of food writing, was no fan of sage: “It deadens the food with its musty, dried-blood scent,” she wrote in Summer Cooking (Penguin, £9.99). Sage is a strong herb, true, so it can elicit a similarly strong response, but I’m pretty sure David was talking about dried sage, which can indeed be very powerful and musty. Fresh sage leaves, on the other hand, all felt-like and smooth, have a glorious, lemony scent and tend to enliven whatever they’re paired with. They retain that power and slightly musty notes, but do so in a way that works harmoniously, rather than dominating a dish.

Sage works best, then, with strong-tasting ingredients that can hold their own against it, which is why anchovies, liver or lemon are the classic pairings. For a quick, simple yet hugely satisfying meal, I often add a few leaves to a small pan of melted butter or hot olive oil, then drizzle it over stuffed pasta. This always feels like a very wise supper decision indeed.

Celeriac and ricotta gnudi with sage butter

The gnudi can be made a day ahead and kept in the fridge. The sauce, however, should be made just before serving, so it stays fresh. This involves a fair amount of effort, but it’s worth it for the sophisticated result. Makes 12 gnudi, to serve four as a first course or two as a main.

½ celeriac, peeled and cut into 2cm cubes (280g net weight)

Finely grated zest of 1 lemon (ie, 1 tsp)

½ garlic clove, peeled and crushed

80g ricotta

30g pecorino, finely grated

1½ tbsp finely chopped basil leaves

Salt

80g fine semolina

1 large egg, beaten

For the sauce

3 tbsp olive oil, plus extra to serve

25g unsalted butter

10 sage leaves

150g cherry tomatoes, quartered and crushed lightly with your hands

20g pecorino, shaved

1½ tbsp basil leaves, roughly torn

½ tsp celery seeds

Put the celeriac in a large saucepan, cover with salted boiling water and simmer for 20-25 minutes, until very soft. Drain, transfer to a plate lined with kitchen paper and lay another sheet of kitchen paper on top. With your hands, gently press down on the celeriac, to help draw out as much liquid as possible; if need be, repeat with fresh paper. You should end up with about 200g cooked celeriac. Mash the celeriac in a bowl – try to get rid of most of the lumps, although a few small ones won’t cause an issue – then refrigerate for 15 minutes, until cool.

Add the lemon zest, garlic, both cheeses, the basil and a pinch of salt to the cooled celeriac and mix to combine. Check the seasoning – you may need a bit more salt, depending on the saltiness of the pecorino – then refrigerate for 15 minutes.

Now organise your work station. Put the semolina on a large plate and out the egg in a bowl next to it. Line a tray with greaseproof paper. Divide the celeriac mixture into 12 pieces and roll each one into a ball that’s slightly smaller than a golf ball, pressing the mixture very tightly with your palms as you roll. Dip each gnudi in the egg to coat, letting any excess drip back into the bowl (use a fork for this stage, if you prefer to keep your hands clean), then roll in the semolina until very well coated, pressing the semolina into the gnudi ball with your palms as you roll. Put the prepared gnudi on the lined tray, then refrigerate for 20 minutes while you get on with the sauce.

Put the oil, butter, sage and an eighth of a teaspoon of salt in a large, nonstick frying pan and place on a medium-high heat. Gently warm through the mix for three to four minutes, until the butter is foaming and the sage is starting to colour, then stir in the cherry tomatoes and take the pan off the heat.

Fill a large saucepan with water, add a tablespoon of salt and bring to a rapid boil. Turn down the heat to medium, so the water is gently simmering, then drop in half the gnudi. Wait for them to rise to the surface – this should take a minute or two – and once they’ve bobbed up, leave to simmer for three minutes more. Scoop them out with a slotted spoon, transfer to a plate, and repeat with the rest of the gnudi.

Once all the gnudi are cooked, add them to sauce and put the pan back on a medium-high heat. Gently swirl around for three minutes, spooning the sauce over the gnudi as you go, until everything is hot. Divide between four plates, making sure each portion gets some sage leaves, and serve with the pecorino, basil, celery seeds and a final drizzle of oil.

Roast salsify, jerusalem artichoke and apple with hazelnuts

The sweetness of salsify root pairs wonderfully well with the earthy artichokes and sage, but it can be hard to find (your local greengrocer may be able to get some for you). A good alternative is an equal amount of celeriac, peeled and cut into batons roughly the same length as the artichokes. Serve this on its own or with roast chicken or pork. Serves six as a side dish.

550g salsify, peeled, rinsed and cut into 7cm-long pieces (400g net weight)

500g jerusalem artichokes, peeled and cut into 5cm-long pieces (450g net weight)

3 tbsp olive oil

5g sage leaves, roughly chopped

Salt and black pepper

20g caster sugar

2 red eating apples (royal gala or pink lady, say), cored and cut into 1cm-wide wedges

60ml dry white wine

1 tbsp lemon juice

50g blanched hazelnuts, toasted and roughly chopped

10g parsley leaves, roughly chopped

5g tarragon leaves

Heat the oven to 220C/425F/gas mark 7. Mix the salsify and artichokes with two tablespoons of oil, the sage, half a teaspoon of salt and a good grind of pepper. Spread out on a large oven tray lined with greaseproof paper and roast for 25-30 minutes, until soft and golden brown (some of the artichoke pieces may need five or so minutes more, in which case leave those in but take out the rest), then leave to cool.

Put the sugar and two teaspoons of water in a medium frying pan and cook on a medium-high heat for two to three minutes, until the sugar has melted and is starting to turn golden brown. Add the apple to the pan and cook for four minutes, turning once halfway through, until caramelised. Stir in the wine, cook down until the liquid has reduced to about two tablespoonfuls, then take the pan off the heat.

Put the vegetables in a large bowl and toss with the apples and syrup. Add the remaining tablespoon of oil, the lemon juice, hazelnuts, herbs, a quarter-teaspoon of salt and a good grind of pepper, stir again gently to coat, then spoon on to a platter to serve.

Swede, bacon and walnut gratin

Yotam Ottolenghi’s swede, bacon and walnut gratin: it’s a sage choice for dinner. Photograph: Louise Hagger for the Guardian. Food styling: Emily Kydd. Prop styling: Jennifer Kay

This works both as a side dish and as a main course with a crisp green salad alongside; it also works without the bacon, if you want to make it vegetarian (you’ll just need to up the amount of salt a fraction). Serves six as a main course or eight as a side.

25g unsalted butter

1 large onion, peeled and thinly sliced (200g net weight)

200g smoked bacon lardons

10g sage leaves, finely shredded

300ml double cream

400ml vegetable stock

1½ tbsp dijon mustard

2 large swedes, peeled, cut in half and then into 3-4mm-thick slices (1.4kg)

Salt and freshly ground black pepper

40g mature cheddar, coarsely grated

40g walnut halves, roughly chopped

Heat the oven to 200C/390F/gas mark 6. Put the butter in a large, 28cm-diameter pot on a medium-high heat. Once it starts to foam, add the onion and bacon, and fry, stirring frequently, for seven to eight minutes, until the onions are soft and the bacon is cooked. Stir in half the sage, the cream, stock, mustard, swede, half a teaspoon of salt and plenty of pepper, bring to a boil, then turn down the heat to medium and leave to simmer for five minutes, stirring every now and then.

Spoon the swedes into a high-sided, 20cm x 30cm ovenproof dish, and pour all the pan juices and bacon bits over the top. Press the swedes down into the dish, and if need be move the slices around, so they’re evenly layered, then roast for 40 minutes, basting and pressing down once more halfway through.

While the gratin is cooking, mix the cheddar with the walnuts and remaining sage. When the 40 minutes are up, sprinkle the cheddar mix all over the gratin and bake for a further 15-20 minutes, until the gratin is dark golden brown and bubbling, and leave to rest for 10 minutes before serving.

• Yotam Ottolenghi is chef/patron of Ottolenghi and Nopi in London.