Remove the seeds from the peppers and roast them at 180 degrees for 30 mins until the skin begins to turn black and the flesh is soft.
Let the peppers cool then remove the skin and chop them into small pieces.
Place the milk and vinegar in a jug and mix well, leave it for five to ten minutes.
Place the flours, bicarbonate of soda and salt in a large bowl.
Add the chopped roasted pepper and the thyme leaves and mix well.
Add the milk and vinegar mixture and stir with a wooden spoon.
The dough will start to come together.
Tip it onto the work surface and bring it together with your hands.
Don't knead or it will get overworked and the bread will be heavy rather than crumbly.
Form the dough into a round loaf and place it on a baking tray dusted with flour.
Using a sharp knife, make two deep slashes on the top of the dough.
Brush the dough with the beaten egg.
Bake at 180 degrees Celsius (fan) for 35 to 40 minutes until deep brown and the base sounds hollow when tapped.
Leave to cool on a rack.