Walla Walla Onion Tart – Washington State

Cathy: Washington State has many famous foods they are known for – salmon, mussels, Dungeness crab, coffee, Rainier cherries, apples – did I say coffee? 🤗 ☕️.

One stop at the famous Seattle Pike Place market will bring you face to face with every kind of seafood imaginable, fresh from the docks.

Washington also has the great advantage of perfect weather for fruit – cherries, apples, blueberries. One of the reasons they call it the Evergreen State.

The state vegetable, though is the humble Walla Walla onion. Walla Walla is actually native American for “many waters.” Sweet, savory and perfect either piled high on a sandwich or burger or caramelized on a tart crust served with a small dollop of creme fraiche. As for the onions themselves, only those sweet onions grown in the federally protected growing area of Walla Walla Valley (also known for good wines) and northeastern Oregon can call themselves Walla Walla Sweet onions. Currently, only about 20 growers grow them. The state’s onion story began nearly a century ago on the island of Corsica, off the coast of Italy. A french soldier found a sweet onion seed and brought it to Walla Walla in the late 1800’s when at the time, the Italian immigrant gardeners comprised the core of Walla Walla’s gardening industry.

I wanted to choose a dish that I could serve as an appetiser as we were having some friends over for dinner and an onion tart was perfect. Often served in the fall or winter warm and savory out of the oven, I baked it earlier in the day and let it cool to room temp and served little squares of the tart with a little dab of rich cold creme fraiche. It was perfect.

Prep time: 1 hour 30 minutes Make a 10 X 14″ tart

Pastry

• 2 cups all purpose flour
• 1/2 tsp kosher salt
• 1 Tbs sugar
• 12 Tbs cold unsalted butter, dished (1 1/2 sticks)
• 1/2 cup ice water

Onion Topping

• 1 cup gruyere cheese, shredded
• 1 1/2 tsp fresh thyme, minced
• 2 tsp fresh chives, minced
• 1 1/4 lbs sweet onions (about 3 medium)
• 1 Tbs heavy cream
• 3 Tbs unsalted butter, diced
• 1 tsp kosher salt

Pastry instructions

(Prepare like you would a traditional savory pie crust – the instructions I followed used a food processor to make the dough but I think next time I’ll just make it like I usually make a pie crust)

1. Place the flour, salt, and sugar in the bowl of a food processor fitted with the steel blade. Pulse for a few seconds to combine.
2. Add the butter and pulse 10 to 12 times, until the butter is in small bits the size of peas.
3. With the motor running, pour the ice water down the feed tube and pulse just until the dough starts to come together. Dump onto a floured board and knead quickly into a ball. Wrap in plastic and refrigerate for at least 1 hour.

Prepare the tart

1. Preheat the oven to 400 degrees and line a sheet pan with parchment paper.
2. Roll the dough between two sheets of lightly floured wax paper, slightly larger than 10 x 14 inches. Using a ruler and a small knife, trim the edges. Place the dough on the prepared sheet pan and refrigerate while you prepare the onions.
3. Sprinkle the rolled pastry with the cheese right to the edges.
4. Sprinkle with thyme and chives.
5. Peel, halve, and very thinly slice the onions into half moons, keeping the moons intact as much as possible. Place the onion half moons on the pastry in diagonal lines, just barely overlapping and brush lightly with cream.
6. Dot with butter and sprinkle with salt.
7. Bake for 40 minutes or until the tart is golden and browned. Cover the edges with foil if the tart is getting too brown during baking.
8. Let cool slightly and cut into squares to serve. Serve warm or at room temperature.

Recipe inspired by Cathy Roma – “What should I make for dinner”.