Add onion and next 3 ingredients to drippings in skillet.
Cook over medium heat, stirring constantly, until onion is tender. Add wine; bring to a boil, and cook until liquid is reduced to about 2 tablespoons.
Add broth, and cook until liquid is reduced by half. Stir in half-and-half.
Return to a boil; cook until slightly thickened.
Pour mixture through a wire-mesh strainer into a bowl; discard vegetables. Return mixture to skillet. Stir in lemon juice, salt, and pepper. Add butter pieces, 1 at a time, stirring with a wire whisk until blended. (If butter is difficult to work into gravy, place skillet over low heat for a few seconds, being careful not to get mixture too hot.)