Meanwhile, for port sauce, in a small saucepan, bring port to boiling; reduce heat. Simmer, uncovered, for 8 to 9 minutes or until reduced to 2/3 cup; remove from pan. In the same saucepan, melt 1 tablespoon of the butter; add garlic and cook for 1 minute. Stir in flour; cook and stir about 1 minute more or until light golden brown. Gradually whisk in reduced port, the broth, demi-glace, soy sauce and 1/8 teaspoon pepper. Stir shallots into port mixture. Bring to boiling, stirring constantly; reduce heat. Simmer, uncovered, for 2 minutes; strain through a fine sieve. Discard shallots.