Step 1

In a large pan, heat butter over medium heat.

Step 2

Peel and thinly slice a large onion. Wash mushrooms and pat dry, then slice into 1/4 inch - 1/2 inch thick pieces.

Step 3

When butter is melted add mushrooms. Place the onions on top and sprinkle with salt and pepper.

Step 4

Let the mushrooms and onions cook, do not stir. After 5 to 10 minutes, check the bottom of mushrooms. If they are brown, stir them to combine the mushrooms and onions.

Step 5

After stirring, cover and cook for another 10 minutes, stirring about once or twice. Do not stir too much. When the onions are tender and start to brown, add Worcestershire sauce and brown sugar.

Step 6

Saute uncovered for another 5 minutes, then serve hot.