We clean all the vegetables. We put the onion through the robot first, then the peppers. Finally we give the mushrooms.
Put half a liter of oil in a large pot and add the onion.
We temper it a little, only until it changes color, we don't let it brown.
Add peppers, mushrooms, tomato paste and the rest of the oil, then season with salt, bay leaves and pepper.
After it starts to boil, turn it on low heat and stir about every quarter of an hour or even more often if you have a pot that you know sticks a bit easily. I boiled the zacusca for about 3 hours.
I washed the jars and put them in the oven tray to sterilize. I left them for about 15 minutes, then I poured hot zacusca. The jars did not break, as the tray was made of metal.
I put the lids on and left them in the oven for another 15 minutes. I let them cool overnight.
I don't think it was necessary to leave them for another 15 minutes, but I did it for more safety.
It is labeled and placed in the pantry.