Buzz
Onions are a staple here at Skillet. Whether raw or cooked, whole or chopped, they add a perfect balance and distinct savory taste to any dish. A favorite way to incorporate the rich complexity of this humble vegetable is in a sauce. This version is inexpensive, creamy (but without the cream), and elevates any meal with a touch of sophistication, all without trying too hard. Enhance your savory dishes with this laid-back soubise sauce.
The traditional soubise sauce is an onion-based variation of the mother sauce, béchamel, which is simply milk thickened with a white roux. The French term seems fitting, as 'white roux onion sauce' doesn’t quite have the same ring. Modern versions of soubise often substitute cream for béchamel, but I stick with the roux for a heartier texture, and my boyfriend can't tolerate heavy cream. (While he can manage some dairy, heavy cream is off-limits.) Traditionally, the roux is first made into a béchamel and set aside. The onions are sautéed in butter and pureed, and then the two elements come together to create the soubise sauce. My approach is simpler, with fewer dishes to wash.
This easy soubise comes together in one go, made all in a single pot with the option to purée. Start by chopping the onion into small bits. I’d describe it as a messy, fine dice, though you can mince it if preferred. The pieces should be no larger than a quarter-inch, unless you plan to purée later. Melt the butter in a medium pot over medium-low heat, then add the diced onion with a generous pinch or two of salt. Stir everything around with a wooden spoon to coat the onions in butter. While that’s happening, warm the milk in the microwave for about a minute until it’s gently steaming. I like using a Pyrex measuring cup, which makes pouring easier later. Stir the onions occasionally, so they cook evenly. They should become soft and translucent, but not caramelized. Lower the heat if the onions start to brown before they’re fully cooked. Don’t worry if they turn a little brown though—it’ll still taste great, but soubise sauce is traditionally a blonde sauce.
Once the onions are fully cooked and softened, add the flour and stir. The mixture will thicken and become clumpy as the flour absorbs the fat. Stir for about three minutes. You'll notice a subtle shift in the aroma, taking on a nutty, toasty smell, and the color will turn golden. These changes are gradual, so if you don't notice them immediately, that’s fine. The goal is to cook out the raw flour taste, which takes only a couple of minutes.
Switch to a whisk and gradually pour the heated milk into the pot. I usually do this in about four pours, but it takes some skill and an apron to avoid splashing. Drizzle and whisk until smooth each time, but keep in mind that the onions will stay chunky (which can be a handy way to disguise any lumps). Take the pot off the heat. If you prefer, you can use an immersion blender to purée the sauce until silky smooth, but I leave the onion chunks as they are.
Whisk in a pinch of black pepper, and you're all set to add it to your dish. The sauce is rich, creamy, savory, and slightly salty, making it perfect for topping roasted meats or vegetables. Soubise also makes a fantastic condiment. Spread it on sandwiches, eggs, eggplant rollatini, or use it as a substitute for tomato sauce on your next pizza. Experiment with spices that complement your dish's flavors—try adding cumin, mustard powder, chipotle chili, garlic, soy sauce, or fresh chopped herbs. You can even make this sauce with non-dairy milk, and while the texture will still be thick and luxurious, the flavor may vary slightly based on the milk you use. Use the sauce immediately, or store it in the fridge, covered, for up to five days. To reheat, just microwave it or warm it on the stove while stirring until smooth.
Lazy Soubise Sauce
Ingredients List:
1 ½ tablespoons butter
½ small onion, finely chopped or minced
½ teaspoon salt
2 tablespoons flour
1 cup hot milk
Pinch of black pepper
In a medium pot over medium-low heat, melt the butter. Stir in the diced onions and salt with a wooden spoon. Let the onions cook until they turn translucent, but avoid browning, about 5-8 minutes. Stir in the flour and cook for another 3 minutes, stirring frequently. The mixture will take on a toasty aroma. Switch to a whisk and gradually pour in the hot milk, whisking until smooth. Add a pinch of black pepper and use the sauce immediately.
