Remove the seeds and veins from the jalapeños. Place them in salted water for one hour, then drain. Next, bring enough water to a boil with salt and a little sugar. When the water is boiling, add the jalapeños and cook for 3 minutes. Remove and drain so they stay crisp.

In a bowl, combine the tuna, diced carrot, diced potato, peas, and mayonnaise. Taste and add more salt if needed.

Stuff the jalapeños with the tuna mixture.

In a saucepan over low heat, add 1 teaspoon olive oil and lightly sauté the sliced carrots and onion. Add the vinegar, a little water, salt to taste, peppercorns, bay leaves, and thyme. Cover and cook until the carrots are tender. Let cool, then use to garnish the stuffed jalapeños.