Yields 1 3/4 cups
In a small (4 cup) pot over medium heat, melt butter. Add flour and whisk periodically as it bubbles into a wet sand texture. Cook until flour smell disappears (2-3 minutes). Add warm milk while whisking vigorously. Add salt and simmer gently using whisk to stir periodically to avoid sticking to the pot corners.
When it begins to thicken (3-4 minutes), if making with rosemary, add sprigs and press into the sauce (avoid breaking off the leaves). Note: 1% milk will thicken slower than whole milk. Keep heat at a low simmer and stir periodically and gently until thick but silky (about 5 minutes). Remove from heat.
Taste. If rosemary is too mild, leave in the pot. Cover with a lid to limit a tough skin forming on the surface before use. Before use or storing, remove rosemary. To store, pour into a bowl and press a piece of plastic wrap over the surface. Store in a refrigerator for several days. Reheat slowly when needed.
Recipe reprinted with permission © 2021 Michele Redmond / The Taste Workshop