First, though, I had to find the mushrooms. So I visited a regular patch on my way to Yakima to speak to the Yakima Valley Mushroom Society. It's a patch frequented by Eastern Europeans, especially Ukrainians, who pick a variety of different Leccinums including what they call "redcaps" (possibly Leccinum aurantiecum, though we're likely to see taxonomic changes in North America with further DNA testing). They leave all the matsutake, which happily went into my bucket, along with several gypsy mushrooms and a fat porcino of more than a pound that remarkably perched in the duff unscathed. When I got home, the gypsies and king bolete went into the strudel.
I've never made a strudel before. For this reason I kept things simple and bought frozen puff pastry from the store. You're welcome to make your own. A couple notes: braiding the puff pastry makes for an attractive presentation and allows air to escape through the vents so that the strudel doesn't blow up into a monstrosity. Dried porcini, though not mandatory, gives the strudel a deep mushroomy flavor. You need less of the mushroom mixture than you think. My next strudel will have a bit less than the one pictured here.
1 oz dried porcini (optional)
1 large shallot, diced
2 tbsp butter
2 - 3 springs fresh thyme, de-stemmed
1/4 cup white wine
1 handful parsley, chopped
salt and pepper
1 sheet puff pastry
1 egg, beaten
1. If using dried porcini, pulverize in a food processor and rehydrate with 1 cup warm water. Set aside for 20 minutes.
2. Saute diced shallot in butter over medium heat until soft. Add diced mushrooms. Cook mushrooms and shallot together for several minutes. The mushrooms will soak up all the butter; add olive oil if necessary. When mushrooms begin to brown, deglaze pan with a splash of wine. Add mushroom stock and reduce until the mixture is moist but not wet. Stir in thyme and parsley. Season with salt and pepper to taste. Remove from heat.
3. Pre-heat oven to 350 degrees. Roll out puff pastry into a rectangle about 12 inches by 8 inches. Place pastry on a piece of baking parchment atop a cookie sheet. With a knife, make diagonal cuts to the edges of the two long sides, so that the pastry can be folded up in a braided pattern. Spoon mushroom mixture down the middle. Fold up the strudel and pinch the ends. Brush with eggwash and place in oven. Bake until golden, about 30 minutes.