Add 1 Tablespoon butter to skillet, saute garlic. Pour the wine into the skillet, scraping browed pieces from the bottom and sides of the pan. Simmer wine until it is reduced by half, about 5 minutes. Whisk in the vegetable broth, lemon juice, lemon slices and capers. Cook for 5 minutes over medium-high heat. Stir in remaining 2 Tablespoons butter and parsley. Continue cooking sauce till thickens, about 10 minutes. Tastes and adjust per liking.