Mix butter, ketchup and paste in small saucepan. Cook over medium heat, stirring, to melt butter; then cook 2 minutes. Remove from heat.
Fill skillet half full of water. Bring to a simmer over medium-high heat. Whisk yolks and water in small metal bowl. Place bowl in simmering water; whisk mixture until thickened, very light colored and registers 140 degrees F for 3 minutes on instant-read thermometer, 5 to 7 minutes total. Remove bowl from water.
Into yolk mixture, whisk ketchup mixture, lemon juice, salt, black pepper, cayenne and pepper sauce. Serve at room temperature. Makes about 1 cup.