Mill black beans at the finest setting or scoop 150g black bean flour into a small bowl.
Add 400g water, whisk, cover and let soak overnight (a minimum of 2 hours, mine was 15 hours).
Preheat your oven to 450F / 230C and make sure there is a rack on the lowest level.
Mix in the salt and 1 Tbsp of the olive oil.
Use the remaining 1/2 Tbsp of oil to grease a 10-12 inch frying pan. I used a 10" cast iron skillet. Make sure the handle is oven-proof.
Put the fry pan on the stove over med-high heat and when the oil is hot, re-whisk the bean mixture and then pour it in the frying pan.
Let simmer 1-2 minutes, then transfer to the bottom rack of the oven.
Bake for 15-20 minutes until the sides are medium brown and there are no shiny wet spots.
Remove from oven and add the fresh herbs to the top of the torta. (This will keep them aromatic and more colorful.) Cool on a rack or your stovetop. Remember the pan and handle are hot.