1 Reduce First Six Ingredients (Clam Juice, Sherry, Whole Milk, Garlic, Shallots, Bay Leaf) By Half In A Small Saucepan, Cooking On Medium To Medium-High Heat. 2 In A Separate Saucepan (1-Qt Minimum) Prepare The Roux. Heat One Tablespoon Of Butter In The Saucepan On Medium Heat Until It Is Foamy. Sprinkle In The Flour, Stirring A Couple Of Minutes With A Metal Whisk Until Well Mixed (But Not Browned). 3 Slowly Add The Reduced Mixture To The Roux, Stirring Quickly To Incorporate. When You First Add Some Of The Mixture, The Roux Will Bubble Up. Just Keep Adding The Mixture And Keep Whisking To Incorporate. 4 Lower The Heat To Low. Slowly Whisk In The Butter, 2 Tablespoons At A Time. Add Lemon Juice, Salt, And White Pepper. Add Some More Clam Stock If The Sauce Is Too Thick.