First, we cook the potatoes and carrot with skin to cook on low heat in a pot with a lot of water and salt until they are al dente.
While they are cooking, we can cook the eggs in another pot with lots of water, boiling it with a pinch of salt for 12 minutes. (You can add a dash of vinegar so that it will be easier to peel them)
If the peas need to be cooked too then we can put them in a pot with water and salt for a couple of minutes and we can save them for later.
We bake the bell pepper, wrapping it in aluminum foil and cooking it in the oven for 5 or 10 minutes; if we are using a piquillo this step is not necessary.
We remove the potatoes and carrot when they are ready, we peel and dice them.
We peel the eggs and cut them into small pieces as well. We mix the potatoes, carrot, eggs, the tuna (without the oil) the bell pepper, and the peas together in a container and we add a dash of olive oil we mix well and put it in the refrigerator.
At the moment you will serve it, let it rest a couple of minutes outside of the refrigerator and we will add the mayonnaise.