TRUFFLE CREAM SAUCE
There are sauces you make because the recipe calls for it, and then there are sauces you make because you simply cannot help yourself. 
There are sauces you make because the recipe calls for it, and then there are sauces you make because you simply cannot help yourself. This one falls firmly in the second category. Built from a well-reduced stock, a good pour of cream, slivers of pancetta, and a few careful drops of truffle oil, it is the kind of sauce that turns an ordinary Tuesday steak into something worth talking about.
What makes it work is restraint. The truffle oil is not the sauce - it is the finishing touch, and there is a big difference. The goal here is a sauce that tastes of chicken, cream, and a whisper of cured pork, with the truffle arriving quietly at the end, not shouting over everything. Get that balance right and you will have a sauce that works with steak, chicken, pasta, or honestly, a very good piece of bread. Four ingredients. A little patience. That is all it takes.
INGREDIENTS
Serves: 4
400 ml (13½ fl oz) good-quality chicken or veal stock, preferably homemade or a good-quality store-bought stock (see Notes)
150 ml (5 fl oz) double cream (minimum 32–35% fat)
60 g (2 oz) pancetta, sliced very thin (or smoked bacon as an alternative)
½ tsp good-quality truffle oil, plus a few extra drops to finish
Salt and freshly ground black pepper to season
MISE EN PLACE
Have a fine-mesh sieve to hand for straining the sauce at the final stage. You will also need a small frying pan to lightly cook the pancetta or bacon separately. If using homemade stock, bring it out of the fridge and have it ready to pour. Slice the pancetta as thinly as possible.
Method
Pour the stock into a medium saucepan and bring to a full boil over high heat. Once boiling, leave to reduce by half. Typically for a homemade stock, reducing by half is enough; for a lighter broth or store-bought stock, start with 500 ml (17 fl oz) and reduce by two thirds. Trust your palate here: taste as you go, and when the flavour is concentrated and satisfying on its own, the reduction is done.
Once reduced, pass the stock through a fine-mesh sieve into a clean pan and bring back to the boil. Add the cream and stir to combine. The sauce will loosen at this point — that is expected. Now reduce again by half over medium heat, stirring occasionally, until the sauce thickens enough to coat the back of a spoon.
While the cream is reducing, place the pancetta in a small cold pan over low heat with no added fat. You are rendering the fat gently, not frying. Remove from the heat once the fat has rendered and the pancetta turns lightly translucent.
Once the cream sauce has reached the right consistency, strain it once more through the fine-mesh sieve into a small saucepan. Lower the heat and add the rendered pancetta pieces. Leave on a very gentle heat for a few minutes, tasting as you go. Season with salt and freshly ground black pepper.
Add the truffle oil — about half a teaspoon is usually enough to perfume the sauce without overpowering it. The truffle should be present but not dominant. If you want a more pronounced truffle finish, add a few more drops of truffle oil just before plating.
Serve generously spooned over a seared steak, pan-fried chicken, or tossed through fresh pasta. A small sprig of tarragon makes an elegant garnish, though the sauce needs nothing else.
NOTES
On the stock: the quality of your base is everything here. If using store-bought, choose a good-quality chicken or veal stock and give it 30 minutes of gentle simmering with a few aromatics - a stick of celery, half an onion, a carrot, a few mushrooms, and ideally a couple of chopped raw chicken wings to boost the flavour.
On the cream: always use a cream with at least 32–35% fat content. Lower-fat creams do not reduce cleanly and can split under heat.
On the truffle oil: most truffle oils on the market are made with a synthetic aroma compound rather than real truffle. They can still be very good. If you can find a quality olive oil infused with actual truffle pieces, the flavour will be noticeably more complex and less aggressive. Use sparingly either way.
On bacon vs pancetta: bacon is smoked pork belly and will bring a smoky note to the sauce. Pancetta is cured but not smoked, with a more delicate, nutty character. Both work, but pancetta is the better choice for a refined sauce finish.