Place the octopus in a pressure cooker covered with water. Let it cook for about 15 minutes.
In a pan put the olive oil with the chopped onion. Then add the chopped garlic cloves and the diced red pepper. After 2 minutes add the tomato also cut into cubes. If necessary, add a little water and cook for about 5 minutes.
Cut the octopus into pieces. Mix the octopus cooking water with hot water to obtain 600ml of water (or 2 + 1/2 cups).
Add the octopus pieces, Oriente rice and the octopus cooking water to the pan. Season with salt and black pepper to taste and cook for about 12 minutes.