In an electric stand mixer fitted with the dough hook attachment, mix the yeast and buttermilk and let sit for 15 minutes. Add in the flour, melted butter, egg yolks, honey, sea salt and pepper and knead on low until everything is mixed together (you may need to scrape down the sides to get everything incorporated) and then turn the machine up to medium for about 15 minutes or until the dough ball becomes shiny and smooth. Add the parmesan and thyme leaves running the machine 1 minute more. Rub 1 tablespoon of oil around a large bowl. Set the dough inside, turning to coat with the oil. Loosely cover the bowl (use a damp towel if the humidity is low) and let the dough double in size…it should take 1 ½ to 2 hours. Then cover the bowl tightly with plastic wrap and set in the fridge for at least 12 hours and up to several days.
When ready to bake, divide the cool dough into two equal-size chunks. Lightly flour a clean surface and roll each piece into a 12 X 9 inch rectangle. Try to make sure the edges are squared off and not rounded. Brush the topside of each dough rectangle with 2-3 tablespoons of Maille Black Truffle Mustard.
With the long side nearest you, grab the two closest edges and fold the dough halfway up the dough, on top of itself. Then, like you’re folding a letter, grab the top edges of the dough and fold them down over the top. Square out the edges of the dough a bit. Repeat with the other piece of dough.
Now we’re going to cut each dough half into 12 strips. I like to use a pizza cutter, but you could also use a very sharp knife, bench scraper or dental floss (I’ve never had much luck with the latter, but maybe you’ll love it). Each piece should be roughly 1 ½ centimeters wide…but don’t stress out on that too much as these are rustic little knots. Each dough log should yield 12 strips of dough, for a total of 24.
Bring a pot of water to a boil. Line several baking sheets with parchment paper.
Grab one strip of dough. Holding each end gently twist the dough moving your hands in opposite directions and then we’re going to tie it into a simple knot. Wrap the dough (adding some more twists if you like) around your index and middle finger and then tuck the ends underneath as you slide it off of your fingers. This is A) a bit messy and B) an imperfect process. Go with it. As you shape the knots place them the prepared baking sheet, allowing several inches in between knots for rising.
Place an oven-safe skillet on the bottom rack of the oven, put the baking sheets with the buns on the top rack of the oven and pour the boiling water in the skillet on the bottom rack. Quickly shut the door and let the dough rise in the cool oven for about 30 minutes or until double in size by the aid of the steam. Take the knots and the skillet out of the oven.
In a small bowl, whisk together the yolk + cream and lightly brush over the knots, taking care not to let any of the egg mixture pool. Sprinkle with a tiny bit of the grated parmesan.
Heat your oven to 350 degrees F and bake the knots in the middle of the oven for 20-25 minutes or until lightly bronzed and an internal temperature reaches 190 degrees F. These are best served immediately.