Box clever: Yotam Ottolenghi’s Christmas leftovers recipes Don’t even think about going to the shops until you’ve dealt with the mountain of leftovers in the fridge

Room for any more? I certainly have! After all the build-up about what comes out of the kitchen on Christmas Day, there’s a huge sense of relief in the days that follow. The pressure is off, expectations revert back to normal and logistics stop being thought through in such detail.

The only problem is how to make use of all the food left over: those roast potatoes you over-catered for, sprouts that never even appeared, the smoked salmon that ended up not being needed, the sweet wine, not to mention the Christmas pudding that defeated everyone.

Leftovers should be just that – using up what you have to hand, rather than having to go to the shops to buy even more – so don’t worry if you don’t have all the ingredients listed here. There’s enough flavour going on in the sweet-and-sour turkey salad, for example, for it to withstand a couple of changes or omissions. You can improvise with the dressing as well: if you don’t have fish sauce, say, just increase the soy sauce to two tablespoons and add an extra squeeze of lime.

It’s time to put away the lists, clear out the fridge and cut yourself some slack.

Smoked salmon and roast potato tart
I’ve used a 4cm-deep tart tin here, to cram in as many leftovers as possible, but if your tin is shallower, just reduce the filling by a quarter. Serves six.

300g shortcrust pastry (homemade or bought in), rolled out into a 30cm round
400g roast potatoes, broken into 2-3cm pieces
150g smoked salmon, roughly torn into 5cm pieces
350ml double cream
3 eggs, lightly whisked
¼ tsp freshly ground nutmeg
5g dill, roughly chopped
10g parsley, roughly chopped
Salt and black pepper
100g creme fraiche
30g unsalted butter

Heat the oven to 180C/350F/gas mark 4. Take the pastry and line a fluted, 24cm-diameter and 3-4cm-deep tart tin, pressing it into the edges. Line with baking paper, fill with baking beans and blind bake for 20 minutes. Remove the paper and beans, then bake for 10 minutes more, until the pastry is cooked through. Set aside to cool slightly.

Lay the potatoes over the base of the pastry shell and dot with the pieces of salmon. Whisk together the cream, eggs, nutmeg, herbs, a third of a teaspoon of salt and a good grind of black pepper, then pour over the potatoes and salmon; you want them to just peek out over the surface. Use two teaspoons to spoon dollops of creme fraiche evenly over the surface, then bake for 30-35 minutes, until the tart is cooked and the top is golden-brown.

Melt the butter in a small saucepan on a high heat for two to three minutes, until golden-brown. The moment the tart comes out of the oven, brush the top with butter and set aside. This tart is best served warm, rather than piping hot.

Sweet and sour turkey salad
Beef, chicken or gammon work just as well instead of the turkey, if that’s what’s left over from yesterday’s menu. If you have more than 200 grams of leftover meat, add more to the salad and increase the amount of dressing as needed. Serves six.

100g flat rice (or mung bean) noodles
½ red onion, peeled and thinly sliced
¼ iceberg lettuce, cut into 2cm-thick slices
2 medium carrots, peeled and julienned
20g picked Thai basil leaves (or normal basil), torn
20g picked mint leaves
40g picked coriander leaves
100g bean sprouts
100g roasted salted peanuts, roughly chopped
3 red chillies, deseeded and julienned
200g cooked turkey, chicken, beef or gammon meat, shredded
30g shop-bought fried shallots

For the dressing
50g palm sugar, finely grated
1½ tbsp fish sauce
2 tbsp cider vinegar
2 tbsp lime juice, plus the finely grated zest of 1 lime
4cm piece fresh ginger, peeled and grated
1 tbsp soy sauce
2 tbsp groundnut oil
1 garlic clove, peeled and crushed

Whisk all the ingredients for the dressing until the sugar has dissolved, and set aside.

Cook the noodles according to the packet instructions (they vary from brand to brand). Drain, then put in a large serving bowl with all the remaining ingredients apart from the fried shallots. Pour over the dre