Flavored ROUX: First, melt butter over medium-high heat, then add the garlic and toast, following with the flour and coat all the flour in the butter.
"Cook-Out" the flour. Allow the flour to absorb the butter. This will help ensure the bechamel sauce will not be grainy.
Next, add in half of the milk and stir constantly. The sauce will try to thicken. Add the remaining milk at this point, little by little. Keep stirring. Allowing the milk to come to a soft boil. (Soft boil means the bubbles are breaking the surface, but not a full boil)
Once at a soft boil, turn off the heat. The sauce will thicken. If the sauce gets too thick for your purposes add a little more milk to thin out the sauce. Remember the heat activates the Roux and thickens.
Add the Nutmeg, to taste. Stir and incorporate
Next, add the "half" Onion with the Cloves attached to the onion.
Cover the pot for a few minutes to allow the flavors to develop.