Boil a large pot of salted water. Peel and cut 2 pounds of starchy potatoes into chunks and cook for 15–20 minutes until fork-tender. Drain and mash until smooth.

Combine the mashed potatoes with 1 egg, salt, and 1–2 cups all-purpose flour gradually until a soft dough forms.

On a floured surface, divide dough into pieces, roll each into a rope about ½ inch thick, and cut into 1-inch pieces. Use a fork to create grooves.

Heat 2 tablespoons olive oil and 2 tablespoons butter in a skillet over medium heat. Add 2 sliced sweet onions and a pinch of salt. Cook for 20–25 minutes until golden brown.

Bring salted water to a boil and cook gnocchi in batches for 2–4 minutes until they float. Transfer cooked gnocchi to the skillet with onions.

Gently toss gnocchi with onions over low heat for a few minutes. Add salt and freshly cracked black pepper to taste. Serve warm.