This French traditional sauce makes your lasagna taste like heaven!
Bring the almond milk with the onion, peppercorn and bay leaves to boil, then turn off the heat and let sit for ten minutes. Meanwhile, make the roux.
Make the roux in a big pot; add the flour to the olive oil and cook for one minute, it's important to keep stirring continually.
Add the milk to the roux and take out the onion and peppercorns by filtering it, and cook for two minutes, until thickened, stir constantly. Add nutmeg, black pepper and salt.