Boil 1 kg of potatoes (with skin) in a large pot of water until they are tender (about 30-40 minutes). Drain the potatoes and let them cool slightly. Once they are cool enough to handle, peel the skin off and mash them using a potato masher or ricer.
In a large mixing bowl, combine the mashed potatoes, 300 grams of all-purpose flour, 1 beaten egg, and a pinch of salt. Mix the ingredients until a soft dough forms. Be careful not to overmix, as this can make the gnocchi tough.
Divide the dough into 4 equal portions. On a lightly floured surface, roll each portion into a long rope, about 2 cm in diameter. Cut the ropes into 2 cm long pieces to form the gnocchi.
To shape the gnocchi, gently press each piece against the tines of a fork or a gnocchi board, rolling it slightly to create ridges. This will help the sauce cling to the gnocchi.
Bring a large pot of salted water to a boil. Cook the gnocchi in batches, dropping them into the boiling water. Once they float to the surface, cook for an additional 1-2 minutes, then remove them with a slotted spoon.
In a separate pan, heat 2 tablespoons of butter and 2 tablespoons of olive oil over medium heat. Add 2 cloves of minced garlic and cook until fragrant. Add the cooked gnocchi to the pan and toss gently to coat them in the garlic butter sauce.
Serve the potato gnocchi hot, garnished with freshly grated Parmesan cheese and chopped fresh parsley or basil.