Chicken and Mushroom in Creamy Sauce

Three things cause a broken sauce. First: cream added to a boiling pan. At high heat the fat separates from the protein. Take the skillet off the heat before adding the cream, then return it to low. Second: cream with too low a fat content. Anything below 30% fat will often curdle when heated. Use heavy cream. Third: parmesan added while the sauce is still on high heat. It goes in at the very end, off the heat, stirred in slowly. If the sauce does break, add a splash of warm chicken broth and whisk vigorously — it usually comes back together.

Chicken breast dries out fast. Two things prevent it. First: slice the breast in half lengthwise to make thin cutlets. They cook in 3 to 4 minutes per side instead of 8 to 10, and it's very hard to overdo them. Second: dredge in flour before searing. The flour crust holds the juices inside. After searing, the chicken goes on a plate while you build the sauce, then comes back for just 1 to 2 minutes at the end — only to warm through. Not to finish cooking.

Cremini give more flavour than white button. Portobello is richer still but releases a lot of liquid and turns the sauce dark brown. White buttons are milder but work well with cream and garlic. A mix of cremini and shiitake is a good option — the shiitake adds a faint smokiness. Whatever you use, the technique matters more than the variety: very hot pan, mushrooms in a single layer, don't stir for the first 2 to 3 minutes. A cool or crowded pan means they steam instead of browning.

The closest result is creme fraiche or full-fat sour cream (at least 20% fat) — they add both acidity and creaminess. Add them off the heat, not into a boiling pan, or they will curdle. Coconut cream from a can gives a very creamy sauce without dairy, though with a faint coconut note — that either works for you or it doesn't. A chicken broth and butter roux gives something closer to a classic velouté than a cream sauce. Regular 10 to 15% cream is possible but the sauce will be thinner and more likely to break.

Three rules. Hot pan — a cool pan and the mushrooms immediately start steaming. Don't salt at the start. Salt pulls moisture out; season at the end of searing, not the beginning. Don't touch them. Stirring right away breaks the browning process and they steam. Lay them in a single layer, use high heat, and leave them until the undersides are golden — then flip. This is the only way to get mushrooms with caramelised edges instead of grey ones.