Mix together the flours, salt, yeast and mixed herbs.
Add 3 tbsp of the olive oil and the warm water. Stir together until it’s too hard to work with a spoon, then knead with your hands until it’s all elastic. The dough will be moist.
Let it rise an hour or more, then punch it down and shape it into a rectangle. Place it on a baking sheet with about a teaspoon of oil rubbed over it. Let it rest about half an hour.
Stretch the dough out to the edges. Let it rest another half hour. Preheat oven to 425F/220C.
Poke some divots into the top of the loaf, then drizzle with the remaining olive oil and sprinkle with sea salt and rosemary. Reduce the oven temperature to 375F/200C and bake for about 30 minutes. Cool on a rack and cut into squares.