Wash the potatoes and place them in a pot with plenty of salted water.

Bring the water to a boil and cook the potatoes until they are tender but not falling apart.

Drain the potatoes and let them cool completely.

Peel the potatoes and slice them thinly.

In a bowl, put the mascarpone, yogurt, and mustard.

Stir vigorously until you get a creamy and homogeneous sauce.

Add salt to taste to the sauce and stir again.

Clean the onion and cut it into coarse pieces.

Blend the onion together with the oil-preserved peppers until you get a homogeneous sauce.

Combine the onion and pepper sauce with the mascarpone, yogurt, and mustard sauce.

Mix well to combine all the ingredients.

Put the potato slices in a salad bowl.

Pour the sauce over the potatoes and gently toss to evenly coat.

Let it rest in the refrigerator for at least 30 minutes before serving.

Serve the potatoes in sauce as a side dish or as a main course.