Place the butter, cream, Tabasco and salt to taste in a small skillet. Bring to a boil and stir gently with a wire whisk until the mixture has the consistency of a rich cream sauce.
Remove the skillet from the heat; stirring rapidly with the whisk, add the egg yolk. Continue stirring and return briefly to the heat. Do not let the mixture boil. Remove from heat and stir in the lemon juice. If the mixture boils again it will curdle. Serve immediately.