I love making sauces - any kind - but there are so many different ones - cooked, uncooked, reduction, etc - are you thinking of a particular technique?
I've just 'mastered' a buerre blanc using a recipe by Tyler Florence; he incorporates a bit of cream into the sauce, and it really does help to stabilize it.
Classic Beurre Blanc: White Butter Sauce
Copyright 2000 Television Food Network, G.P. All rights reserved
1/3 cup champagne vinegar
1/3 cup dry white wine
2 shallots, finely chopped
1/2 lemon, juiced
2 bay leaves
1/2 cup heavy cream
1/2 pound (2 sticks) unsalted butter, cubed
Salt and pepper
2 tablespoons chopped chives
In a heavy 2-quart saucepan, combine vinegar, wine, shallots, lemon, and bay leaves to make an infusion. Simmer over medium heat for 5 to 8 minutes until the mixture is reduced to a wet paste, about 2 tablespoons. Add the cream and continue to simmer until reduced again to about 2 tablespoons. Cream is added to make the sauce more stable and less likely to separate.
Reduce the heat to low and remove the bay leaves. Whisk in the chunks of butter in small batches. The butter should melt without the sauce getting too hot, producing a creamy emulsified sauce. Do not let the sauce go over 130 degrees F, where it will separate. If the sauce starts to break, remove from heat, add 2 ice cubes and whisk until it cools down and comes back together. Season with salt and pepper, fold in the chives, and serve immediately. Keep covered in a warm place for a few hours, if needed.
Serve with fish or vegetables.
Yield: 1 cup
Made this for softshell crabs at Christmas, and added tarragon and capers - yum!