Get out and measure all of your ingredients.
In a large Dutch oven, over medium high heat, melt butter. Add the sweet potatoes, salt and pepper.
Add brown sugar and water.
Stir until blended.
Bring to a simmer. Reduce the heat to medium low, cover, and cook until sweet potatoes are fork tender, 45 to 60 minutes. Stir regularly.
When the sweet potatoes are tender, remove the lid and bring the sauce to a rapid simmer over medium-high heat. Continue to simmer until the sauce has reduced to a glaze, 7 to 10 minutes.
Adjust an oven rack to the middle position and heat the oven to 450 degrees. Pour the potato mixture into a 13 by 9-inch baking dish (or a shallow casserole dish of similar size).