Clean your mushrooms with a damp paper towel to remove dirt. Slice them into even pieces. Do not wash them under running water or they will get soggy.

Heat olive oil and one tablespoon of butter in the skillet. Add the mushrooms in a single layer. Cook them until they turn golden brown and look delicious.

Add the remaining butter to the pan with the mushrooms. Stir in the chopped shallots and minced garlic. Cook for two minutes until the shallots look soft and clear.

Pour the Marsala wine into the hot pan. Use your wooden spoon to scrape the brown bits off the bottom. These bits hold all the best flavor for the sauce.

Let the wine bubble and simmer for about five minutes. You want the liquid to reduce by half. This step makes the Ingredients for Marsala Mushroom Sauce blend together perfectly.

Pour in the chicken or vegetable broth and add the fresh thyme. Let it simmer for another three minutes. This adds more depth to the savory profile of your sauce.

Lower the heat and pour in the heavy cream slowly. Whisk gently to combine everything into a smooth liquid. The sauce will start to look rich and velvety.

Keep the heat low and let the sauce simmer for two more minutes. It should be thick enough to coat the back of a spoon. Do not let it boil hard.

Taste the sauce carefully. Add salt and pepper according to your preference. Sprinkle fresh parsley on top right before you serve it to add a pop of color.