Transfer the dough into a bowl and round it into a ball by rounding and tucking it up under itself to create tension across the top as shown in the video @0:54.

Cover the bowl with a lid or plastic wrap and ferment for 90 minutes in a warm environment. To create that "warm environment" I turn my oven on at 350F/175C for about 2 minutes, then turn off the heat, creating a nice warm 90F/32C box where the dough can ferment.

After 90 minutes, the size of the dough should have about doubled. If it hasn't yet doubled, continue to ferment for a bit longer.

Divide dough into 6 equal pieces that are about 100g each. Degas each piece with your fingertips and shape into balls, using your fingertips and palms while rolling against your work surface to create tension across the top of the balls as shown in the video @1:24.

Place shaped balls onto a parchment lined sheet tray. Cover the tray and proof again at 90F/32C for 45-60 minutes. The individual buns should have doubled in size (if not, keep proofing until they have).

Brush each bun with egg wash and top with a spoonful of the cooled caramelized onions (recipe below), spread as evenly as possible over the top of the bun. Follow the onions with a pinch of poppy seeds and flaky salt.

Bake at 400F/205C for 15-17 min until golden brown, but still soft.

To make the onions to top the bun, very small dice 1 medium vidalia onion.

Add a bit of olive oil into a saute pan over medium heat and add in the onions, a pinch of salt, a pinch of sugar, and the 1/4c or 50g of water. Simmer to soften the onions and once the water has simmered off (about 2-3 min) then continue to saute for another 4-5 minutes or until the onions have taken on some light browning. Deglaze the pan with a few more spoonfuls of water. When the water has evaporated, saute for another 4-5 minutes while stirring constantly. When done, the onions should be a nice golden brown and have almost a sticky consistency. Spread the onions out on a plate to cool.

Preheat oven to 550F/285C (or as high as your oven will go).

Rub olive oil liberally onto all sides of the beef.

Place the roast on a wire rack on a sheet tray. I also like to put a piece of foil underneath the wire rack to make clean up easier.

Very liberally salt and pepper all sides of the roast.

Load the roast into your hot oven to "sear" the outside for 15-20 minutes (use convection if you have it). Reduce the oven temp to 275F/135C and after about 10 minutes or so when the oven temp has cooled to 275F/135C, load the roast back into the oven to roast for 2 hours.

After 90 min to 2 hours, check the internal temperature of the meat with a meat thermometer. You're looking for around 130F/55C.

Remove beef from the oven and allow it to rest for at least 30 minutes before slicing.

Mix with an immersion blender

Add corn starch to cheddar and mix well to coat. Use the largest holes on a box grater to grate your own. Packaged pre-shredded cheeses often include anti-caking agents that make them melt in a weird way.

Add the cheese corn starch mixture into a medium sized saute pan then add in evaporated milk. Heat over low heat and stir frequently to melt for about 5 minutes.

When mixture reaches a low simmer it should start to thicken. Be sure to scrape the bottom of the pan well with a spatula or wooden spoon to prevent scorching. If the mixture gets too thick, stir in a splash more evaporated milk.

Slice an onion roll across, and toast in a well buttered pan until toasty and golden brown.

Slicing the meat: If you don't have access to a meat slicer, you can use a "slicer" knife to slice the meat as thinly as possible. We're going for shaved pieces here. Thicker pieces will give you a more steaky, chewy texture and that's not what we're going for. If you DO have a meat slicer, use that to shave the beef very thin.

Add a generous amount of tangy sauce to the bottom bun, followed by a handful of your shaved beef slices. Top with a few large spoonfuls of the cheese sauce and the toasted top bun. Squish and enjoy.