A good pan sauce can be impressive—luxurious even—but it all hinges on the consistency. A too-thin sauce feels watery on the tongue and runs all over the plate, but it’s no reason to panic. You can fix yours with two cheap and ubiquitous kitchen staples.
There are a ton of different ways to add body to a sauce, but I usually like to fix my pan sauces with a beurre manié, or “rax roux,” because I love an excuse to add butter to anything. To make it, mash an equal amount of flour and butter together to make a paste. The butter coats the flour, allowing the starch absorb water, swell, and work its thickening magic without clumping, while the fat in the butter keeps the sauce from running by slowing things down with its long, tangly molecules. It’s an iconic duo, and the only criticism I have of this method is that it takes a few minutes more than I would like it to. But according to Cook’s Illustrated, there’s an even faster way to thicken your sauce with butter and flour.
It turns out you don’t have to make a paste at all. There’s no need to get your fingers messy, no need to mush and mash butter and flour together; you can simply cut the butter into cubes and toss them in the flour. Cook’s Illustrated recommends a ratio of 3 tablespoons of butter and 1 teaspoon of flour. Cut the butter into 1/2-inch cubes and toss them with flour until no excess remains. Stash the cubes in the fridge, then toss one or two (or however many you need) into your next runny pan sauce. Whisk them in and let the sauce simmer for a few minutes until it is as thick and luscious as you desire.