Garlic and Onion Boiled Peanuts

Melt butter in a large pot over medium heat. Stir in the onion and garlic; cook until softened and transparent, about 10 minutes. Turn off the heat. Add the peanuts and salt to the onion mixture. Fill the pot with water until the peanuts are submerged, and use a large colander fitted into the pot to hold them under water. Bring to a boil, then lower the heat to medium, and simmer. Check the water level, and when it reaches the level of the peanuts, add more. Turn up the heat to medium-high and bring the peanuts to a boil; the lower heat to medium, and simmer. Repeat steps until peanuts are soft, 4 to 6 hours. Drain, and serve hot or cold.