In the bowl of an electric stand mixer fitted with the dough hook attachment, add the warm milk, yeast and honey and let mingle for about 10 minutes until foamy and frothy (this lets us know our yeast is working). Add in the flour, potato flour, butter, egg and sea salt and mix on low at first, working your way up to medium high. Run the machine for 10 minutes. The dough will stick to the bottom of the bowl but should be clearing the sides. Some minor sticking on the sides is fine. The dough should smooth out the longer it is kneaded. Make sure to scrape the sides and bottom of the bowl so that everything is incorporated.
Lightly grease a large bowl with olive oil. Scoop the dough into this bowl and let rest for 1 1/2 hours or until double in size. **At this point, the bowl could be covered tightly and stashed in the fridge for 24 hours. When ready to use, just move onto the next step, no need to bring the dough to room temperature.
In a small bowl toss the shredded cheddar with the minced thyme (if using). Set aside. Lightly grease and line a 9x13 baking dish with parchment, letting the excess hang over the sides…this will make it easier to lift the rolls out of the dish.
When read to bake, separate the dough into 15 equal-sized pieces. Total dough weight should be about 789g; each dough ball should weigh roughly 52g. Roll the pieces into balls and then flatten them into about 2-inches circumference (no need for a rolling pin, you can use your hands). Fill with 1 1/2 tbsp of the gruyere-thyme mixture. Grab the edges of the dough and pinch them together to seal the cheese in the middle. Place the seam side down and gently roll until they’re a perfect little ball again. Set the balls, even-spaced apart from each other, in the prepared baking dish and cover loosely with a damp dish towel. This is a perfectly imperfect process. Some cheese will spill out, that’s fine. Let rest for 30-60 minutes or until almost double in size in a warm, draft-free area.
Preheat your oven to 350F (177C).