Gâteau de Nillon – A Delicious By-Product of Nut Oil Pressing

One of my favorite weekend activities in Switzerland is attending small, regional food and tradition festivals.  The latest one was the Autumn Fair and Cowbell Market, an incredible event held above the charming, tiny village of Romainmôtier in French-speaking Canton Vaud.

We made the long trek (four trains and a shuttle bus) on a beautiful, sunny autumn Saturday.  The views on the way up the mountain to the Romanesque village were spectacular.

The festival was everything I could hope for in a regional fair – packed with friendly locals, cows descending from the mountains for the winter, a cowbell ringing club performing, used cowbells for sale and regional food and drink galore.

I always look for unfamiliar products at regional markets.  While browsing around, I spotted rectangular bars labeled Nillon. They looked like the pressed wood shaving blocks I buy in winter to start a fire in my fireplace.

Next to the bars were bags filled with what looked like very finely ground nuts labeled the same.

The vendor gave us a small chunk to nibble on.  It was the consistency of soft, pressed sawdust with a nutty flavor.  He explained that Nillon (more typically spelled Nion as I discovered upon returning home and doing research) is the residue left behind after pressing nut oils. Basically, it is the milled nut after the oils are extracted.  He said it could be used a number of ways including in cake or coating fish before sautéing.  I bought a bag along with a bottle of his freshly-pressed nut oil and decided to attempt both.

The baby Swiss perch we bought at a tiny market in the castle town of Murten/Morat that morning tasted fantastic dipped in milk, dredged in Nion seasoned with salt and pepper then sauteed in the fresh-pressed nut oil.

My big challenge, though, was making a traditional Nion Gâteau. This delicious tart has a subtle nutty flavor and the consistency of traditional American pumpkin pie made with fresh pumpkin (which is not as smooth-textured as when using canned pumpkin puree).  Well worth hunting down this unique byproduct.  If unavailable, finely ground walnuts, pecans or almonds may be substituted, although the taste and texture will differ slightly.

I found several recipes but ended up developing my own which is an amalgam and remains authentic. This printable, text-only recipe is at the bottom of the post.  Normally I make my own tart and pie crusts but decided to use store-bought to simplify preparation.  By all means substitute a favorite pâte brisée short crust recipe.

The filling ingredients include milk, cream, an egg, butter and nion.

Measure or weigh out ground nion.  

Measure out milk.

Pour the milk into a pan.

Heat until it just begins to simmer.

Turn off the heat and add the nion.

Stir to combine.

The mixture should sit about 2 hours.  After one hour, give it a stir and break up any lumps.

Transfer the now-softened nion and milk mixture to a mixing bowl.  Add the egg and softened butter.

Beat until smooth.

Some recipes sweeten the filling with a local product called vin cuit (pear juice, sometimes with apple juice, slowly cooked for 24 to 48 hours until it is reduced to the consistency of molasses).  Other recipes use sugar.  I have several jars of vin cuit in my pantry but thought sugar an easier option.

Add heavy cream.

Beat until incorporated.

Unroll a purchased, chilled tart crust or roll out a homemade, chilled pâte brisée (short pastry).

Press it into a buttered or parchment-lined tart pan.

Using fingers or a rolling pin, go over the top ridges of the pan,  This cuts the dough.

Pull away the excess dough.

Tap a fork around the base of the pan.  This will prevent the dough puffing up during baking.

Spread jam (I used raspberry) or vin cuit thinly over the crust.  OK to skip this step.

Place the tart pan on a large, flat baking sheet.  The baking sheet makes transporting the filled tart crust to the oven easier and will catch any spillovers during baking.

Slowly pour the filling over the crust.

Place in a pre-heated oven.

Bake about 30 to 40 minutes, or until center gently giggles when the pan is lightly shaken.

This delicious tart is not too sweet.  It has the consistency of traditional American pumpkin pie made with fresh pumpkin (which is not as smooth-textured as using canned pumpkin puree) and has a subtle nutty flavor.  Well worth hunting down this unique byproduct.

Nion is available at some local festivals and farmer markets in nut-producing regions of Europe.  Look for vendors selling nut oils and nuts in shells. It can also be mail ordered from small mills pressing oil such as Huilerie De Severy in Switzerland.