Mornay Sauce

• 43 grams unsalted butter
• 65 grams ¼-inch dice Spanish onion

Melt the butter in a saucepan on a diffuser over medium heat. Add the onion and a pinch of salt and cook slowly until the onion is translucent. Sprinkle in the flour and cook, stirring constantly so the roux does not color, for about 3 minutes. Whisking constantly, add the milk and cream, whisking until fully incorporated. Bring to a simmer, then add the bay leaf, peppercorns, and cloves. Move