Sourdough Potato & Birdseed Brioche Buns

Directions

1. The evening before you make the brioche dough, you’ll want to prepare the leaven and poolish. It takes at least 8-12 hours for them to develop fully. Start with 2 clear containers. I find that an 8oz jar is about the right size for this recipe. For the leaven, drop your starter in one of the containers. Stir in the water, whole wheat and all-purpose flours to form a smooth paste. Cover the container and leave it out on the counter overnight. For the poolish, stir together the water, all-purpose flour and yeast to make a smooth paste. Scrape any poolish on your spoon into the container. You’ll need every bit. Close the container and pop it in the refrigerator overnight.
2. First thing in the morning, check on your poolish. If there are few if any bubbles forming on the bottom and sides of the container, set it out on the counter to finish developing. Your leaven and poolish will be ready to go when they are very bubbly and have roughly doubled in size. A spoonful will float when dropped in a container of water. Be sure to rescue any bits you drop in water. You’ll need it for the dough. At this point, take the butter out of the fridge to allow it to soften at room temperature while you mix the dough.
3. Prepare your stand mixer with the paddle attachment. Drop 2 eggs, 1 egg white, milk, leaven, poolish, salt, sugar and active dry yeast into the mixer bowl. Save the spare egg yolk in a separate container for later. Stir the ingredients together on low speed. Measure the whole wheat and bread flour into a separate container. Then, sprinkle it into the mixer a little at a time to avoid a floury explosion as you continue stirring. Stop and scrape down the sides of the bowl after all the flour is added. Then mix until the ingredients are well incorporated. Cover the bowl and let rest for 15-20 min.
4. While the dough is resting, toast the seeds in a small skillet on medium heat stirring until they begin to brown and smell nutty. Mix the seeds together with the mashed potatoes in the empty container you used for the flour and set it aside to cool.
5. Change out the paddle for the dough hook on your mixer. Stir the dough at medium speed for 2-5 min. or until the dough pulls away from the sides of the bowl. At that point, the dough is ready to incorporate the butter. Slow the mixer to low speed. Using a spatula, scrape roughly 1/2 tablespoon sized lumps of butter into the mixer, waiting for each one to disappear into the dough before adding more. Be patient, the colder your butter is, the longer it may take to mix in. It’ll take about 10-15 min. to incorporate it all. At this point, your dough will look smooth and glossy. Add in the mashed potatoes and seed mix, stirring until it’s blended into the dough.
6. Cover the bowl. For the next 2 hours of bulk fermentation, let the dough rest, checking in to turn the dough every 30 min. Turning the dough is a slightly different action from kneading. Instead of punching or rolling the dough, the idea is to gently fold it over on itself to preserve the air bubbles being formed by the yeast. Wet your hand or a spatula with water to avoid sticking to the dough. Imagining your dough as a square, slide your hand or spatula down the inside of the bowl and underneath the dough. Gently lift and fold the dough up and over the center, repeating for each side of the “square”. Once you’ve folded over all 4 “sides” you’ve completed one round of turning the dough.
7. After the bulk fermentation, you can stop and put your dough in the freezer if you want to finish the rolls another day. It can live happily in there for up to a few weeks. Just move the container of dough to the fridge the night before you plan on baking. A couple of hours before you are ready to bake, turn the dough out onto a floured countertop. Cut it into 12 even pieces, roughly 90-95g each. Shape them into round balls by cupping the dough in one hand and gently tucking the edges toward the center until you have a round top in your palm. Space them out evenly on a sheet pan lined with parchment, gathered side down. 12 rolls will fit on a half-sized sheet pan but may touch each other as they rise and bake.
8. Cover the tray with a clean kitchen towel and let the rolls rise at warm room temp for 1.5-2 hours. If your kitchen is on the cool side (70 F or cooler), place the tray in the oven with the oven light on. Don’t worry if the rolls don’t rise dramatically, but they should look round and a little larger at the end of the final rise.
9. Preheat the oven to 450 F. Take the spare egg yolk you set aside earlier and mix it with about a tablespoon of water or milk to make an egg wash. Brush the tops of your rolls with the egg wash. This will help them develop a shiny, golden-brown top. If you like, you can sprinkle some additional oats, millet and sunflower seeds on the rolls as well. Bake them for 15 min. or until they are puffy and golden brown. Let them cool a while before eating if you can resist.