In a large bowl, add flour, instant yeast and salt together. Roughly combine.
Add 2 heaped tablespoons of Dijon Original Mustard to the lukewarm water and mix until dissolved. Add the water to the flour mixture. Mix until well combined. Cover the dough with cling wrap or a damp cloth and place in a warm area and allow to double in size, about 90-120 minutes. Note: if you are experiencing cooler weather then feel free to preheat the oven to 40℃/104℉ and place the covered dough in the oven to rise.
Meanwhile, make the filling. Bring a medium saucepan to a medium-high heat, add olive oil, onions, thyme and salt topgether. Sauté the onions until softened and turning golden brown. Finish off with Dijon mustard and transfer to a medium bowl and allow to cool. Add biltong and cheese to the onions and mix until well combined.
Tip the risen dough onto a lightly floured surface, dust with a sprinkling of flour and gently spread the dough into a circle with approximately 30cm radius. Coat the dough with 1/2 of the filling and fold the left side over to the middle, add 1/2 of the remaining filling, then fold the right side over the lift side and top with the remaining filling, then fold/roll the top half way all the way down (see video for reference).
If you're using coals, place the dough (with the seal at the bottom) in a buttered iron cast pot. When baking, make sure there's enough coals to place below the cast iron pot as well as on top as this will ensure an even bake. You can also gradually turn the pot ensuring one area doesn't get more heat than the other (remember low and slow if the key). Bake for 40 minutes. After 30 minutes you can lift the lid and adjust the heat. Note: lining the pot as well as the lid with butter will ensure for an easy release once baked. If the bread sounds hollow when you tap it, that's when you know it's ready.
If you're using the oven, preheat the oven to 240°C/450°F (220°C fan). Half an hour before the dough is ready, put a 24-28cm heavy based pot/Dutch oven with a lid in the oven to preheat. Transfer the folded dough onto a large square piece of baking paper (but small enough to fit in the Dutch oven). Remove the hot pot from the oven, and using the baking paper to lift the dough, place it in the hot Dutch oven, cover and pop it bake in the oven. Bake undisturbed for 35 minutes, then remove the lid and bake for another 10.
Tip the freshly baked bread onto a clean surface and serve with salted butter. Enjoy!
