Use a damp paper towel to wipe down the mushrooms. If they are loaded with dirt, then rinse them off with water and place them on a paper towel to drain. Remove any excess water with paper towels.
Cut the mushrooms in half, remove the stems and slice them. Collect the sliced mushrooms in a zip lock gallon plastic bag.
Add the fat free Italian dressing to the bag with the mushrooms. Seal the bag, removing as much air as possible.
Gently massage the bag of mushrooms to distribute the Italian dressing. Lay the bag on its side and let the mushrooms marinate while you prep the other ingredients.
Slice and chop the onion and bell pepper into small pieces.
Heat the olive oil in a skillet. Add the chopped onion and pepper to the skillet. Sauté the onion and pepper until they are tender.
Add the mushrooms and marinade to the skillet. Stir them into the onions and peppers. Sauté the mushrooms until they are cooked. Once they are cooked, continue to cook them until most of the marinade has evaporated.
Add the garlic powder, salt and pepper to the sautéed vegetables. Taste and adjust the seasoning to your liking. You are looking for a subtle garlic flavor.
Transfer the mushrooms, onions and peppers to a serving bowl to serve them as a side dish with a protein or transfer them to a storage bowl if you are preparing them as an ingredient for another dish.
Refrigerate any left overs.
Notes
Nutritional info and points were calculated using Kraft fat free Italian zesty dressing.If you substitute a different Italian dressing, adjust points.