Combiine the wine, vinegar, lemon juice, garlic, and shallots in a medium saucepan. Boil over high heat, reducing the liquid until about 1/4 cup remains. Slowly whisk in the butter, making sure you keep the temperature even, not too hot or too cold. When all the butter has been added and you have a creamy smooth sauce, season with salt and pepper to taste.
Serve immediately. Do not try to hold the sauce longer than 1 hour. Enjoy!