A Sauce by Any Other Name

A few weeks ago, I was leafing through some recipes that I used for my cooking classes way back when. I came across an old favorite, Asparagus with Mousseline Sauce and Hazelnuts. Yum!

Asparagus is plentiful in Paris right now – both the green and white varieties. So my recipe jumped off the page: I thought this old chestnut (er… hazelnut?) would make a great addition to the blog, as well as a delicious lunch.

The mousseline sauce is wonderful: light, airy, and with a slight tang, it complements the asparagus perfectly, and the roasted hazelnuts add the nutty crunch that rounds out the variety of textures.

Asparagus with Mousseline Sauce and Hazelnuts

Thunder approached

But what, exactly, is mousseline sauce? You probably know that French sauces have a reputation for being notoriously complex, both in name and in execution. You’ve got the mother sauces, and then all those derivative sauces, or what Escoffier called the “small sauces.” In all, there are nearly 200 sauces in French cuisine! But mousseline sauce is relatively easy: it’s nothing less, nor more, than a basic Hollandaise sauce into which you add whipped cream.

Asparagus with Mousseline Sauce and Hazelnuts

Don’t be fooled: these asparagus at a local organic shop are gorgeous, but I would never pay these prices! Market finds are cheaper.

But just for fun – yes, this is my idea of fun – I wandered onto Google to see some other iterations of the classic sauce. I must be a glutton for punishment, because this is where my sky suddenly filled with dark clouds. Rumblings of thunder approached as I clicked through page after page of radically different recipes for mousseline sauce.

French (Food) Revolution

Gulp! There they were: on the vast toile, or net, were recipes for a mousseline sauce made with… mayonnaise and whipped egg whites?! What was this, I thought, some kind of French (Food) Revolution??

The ground began quaking under my feet. (Or, probably, it was just the endless travaux, or renovations, going on in our building.) Everything I thought I knew about French food was going up in smoke, as it were.

Asparagus with Mousseline Sauce and Hazelnuts
Asparagus with Mousseline Sauce and Hazelnuts
Asparagus with Mousseline Sauce and Hazelnuts

My neighbors are literally raising the roof on our building right now, and it looks like this will go on all summer!

Old Cheese Rinds?

I began losing sleep, and thought I was even losing my mind. The next day, would I wake up to find that the classic béarnaise sauce was made with tofu? (I’m sure this exists.) Or that a velouté sauce was thickened with old cheese rinds, or at least the few that my daughter didn’t stuff into her mouth? What was going on?

But then I got a grip and started checking around in my personal resources (otherwise known as cookbooks) and found, much to my relief, that the mousseline sauce I know and love was still there, intact.

Emulsified Sauces

One of my favorite French cookbooks, the creatively named French Cooking, has four pages of detailed tables on emulsified sauces and thickened sauces. And right there, on the bottom of page 127, we have the category of “semi-coagulated egg yolk” sauces. Whew!

I’d forgotten what a Mikado sauce was (Hollandaise + juice and zest of mandarin orange), or a Choron sauce (Béarnaise without chervil or tarragon + tomato). A sigh of relief later, I sat back and read (at leisure) the tables in the following pages.

Julia Child

And then Julia Child, bless her heart, came to my rescue as well. There it is, right on the page: Sauce Mousseline or Hollandaise with Whipped Cream. 

But wait…. It’s also called Sauce Chantilly?! But I learned many years ago that Chantilly is a specific appellation in France, referring ONLY to a blend of whipped heavy cream, confectioner’s sugar, and vanilla bean! Oh, no! Here we go again… Vive la cuisine française!

Asparagus with Mousseline Sauce and Hazelnuts
Asparagus with Mousseline Sauce and Hazelnuts

Asparagus with Mousseline Sauce and Hazelnuts


  • 20 spears fresh white or green asparagus (about 1.8 pounds (800 g) if using green asparagus, or 2.6 pounds (1.2 kg) if using white, or about 20 spears), or a mix of both colors!
  • ½ cup (60 g) hazelnuts

for the mousseline sauce:

  • 8 tablespoons (125 g) high-quality butter
  • ⅛ cup (30 g) heavy cream, very cold
  • 3 egg yolks, from very fresh eggs
  • ½ teaspoon salt
  • ½ lemon, squeezed

special equipment (optional): immersion hand blender with whisk attachment (a stand mixer is too large for the quantity of whipped cream)


how to make it:

  1. Preheat the oven to 300°F (150°C).
  2. Make the clarified butter: cut the butter into dice-sized cubes and place them in a small narrow pot. Heat over low for 10-20 minutes. The butter will sputter as it’s giving off its liquid. When you see clumpy milk solids on the top, and translucent butter (fat) underneath, turn off the heat.
  3. Roast the hazelnuts in a shallow oven baking sheet for about 25 minutes, shaking it once or twice, until you begin to smell a wonderful hazelnutty smell in your kitchen. Let them cool directly on the baking sheet and then transfer them to a small bowl. Once cooled, chop the hazelnuts.
  4. Skim the milk solids from the top of the butter, then pour the butter through a fine-meshed strainer, stopping before you reach the milk solids that have settled at the bottom. Reserve the clarified butter at room temperature. (You can throw away the leftover milk solids.)
  5. Using an ordinary hand whisk or immersion hand blender with whisk attachment, whip the heavy cream to medium peaks. Leave it out at room temperature.
  6. Snap the asparagus spears and peel if necessary (for white asparagus). Steam for about 8-12 minutes, or just until al dente. The spears should be slightly firm. Leave the asparagus in the steam basket.
  7. In a small saucepan, beat the egg yolks with 3 tablespoons of water over medium-low heat, whisking in an 8 pattern constantly. First the mixture will become foamy, and gradually the bubbles will become smaller and smaller until the sauce thickens and becomes very shiny. If at any time during the process, you see steam coming from the pan, momentarily take it off the heat and keep whisking. Eventually you’ll see the bottom of the saucepan when you whisk. Remove from heat and add the salt.
  8. Still off the heat, slowly whisk the clarified butter into the egg yolks in a small stream. Add the lemon juice, and gently fold in the whipped cream.
  9. Serve the asparagus on a platter or divide between 4 small plates. Gently spoon the sauce over the asparagus spears, and sprinkle with the hazelnuts. Serve the extra sauce and hazelnuts on the table for your guests. Bon app’!

makes 4 first-course portions



Asparagus with Mousseline Sauce and Hazelnuts
Asparagus with Mousseline Sauce and Hazelnuts