Slice top off garlic to expose the cloves

Lay the garlic on a sheet of heavy-duty aluminum foil and drizzle with olive oil

Wrap garlic in foil and roast at 400 degrees for 1 hour

Cool slightly and then squeeze the garlic out into a blender

Add 1/2 cup chicken broth and puree

Peel and finely chop the shallot

Melt 1 tablespoon butter in a 3 quart saucepan over medium high heat

Add the shallot and toss until tender, about 2 minutes

Add the port and bring to a boil, scraping up any browned bits from the bottom of the pan

Cook until only 2 tablespoons port remain

Add the garlic broth mixture and the remaining chicken broth to the saucepan and bring to a boil

Cook until liquid is reduced by half

Remove from heat and whisk in the remaining 2 tablespoons butter

Season to taste with salt and pepper.