Peel the potatoes and cut them into thick French fries. Rinse the fries with cold water and pat them dry with a paper towel. Heat a deep fryer or a large pot of oil to 375°F (190°C). Fry the potatoes in batches until they are crispy and golden brown, about 5 to 6 minutes per batch. The fries should be taken out of the oil and allowed to drain on a dish covered with paper towels and season with salt to taste. In a small pot, melt the butter over low heat and keep the butter warm until ready to use. In a separate pot, heat the beef gravy over low heat and keep the gravy warm until ready to use. To assemble the poutine, place the hot French fries in a large bowl. Sprinkle the cheese curds on top of the fries, making sure to distribute them evenly. Pour the hot beef gravy over the fries and cheese curds. Drizzle the melted butter on top of the gravy. Serve immediately and enjoy! Note: The key to a good poutine is to use fresh cheese curds and hot gravy. If you can't find cheese curds, you can substitute with a good quality cheese that melts well, such as cheddar or mozzarella.