Melt butter in 1 quart saucepan; whisk in flour. Cook and stir over low heat 2 minutes.
Gradually whisk in milk. Cook and stir about 2 minutes until smooth and thickened.
Stir in lemon juice. Gradually mix in cheese. Add pepper sauce and salt. Cook and stir until smooth.
Serve hot over asparagus cooked crisp-tender. Garnish with lemon wedges, if desired.
Servings: 6