Step 1: Prepare the Potatoes

1. Thoroughly scrub the potatoes under running water to remove any dirt. If using larger potatoes, cut them into 1–1.5-inch pieces to ensure even cooking.
2. Place the potatoes in a large pot and cover them with water. Add 1 teaspoon of salt to the water to season the potatoes as they cook.
3. Bring the water to a boil and let the potatoes cook for about 15-20 minutes, or until they can be easily pierced with a fork. Avoid overcooking, as they should remain firm enough to hold their shape in the sauce.
4. Once cooked, drain the potatoes and set them aside.

Step 2: Cook the Mushrooms and Onions

1. While the potatoes are cooking, clean the mushrooms by gently wiping them with a damp paper towel to remove any dirt. Avoid washing them under running water, as they can absorb excess moisture.
2. Slice the mushrooms into ¼-inch thick pieces.
3. Peel and finely dice the onion.
4. Heat 1 tablespoon of olive oil in a large skillet over medium-high heat. Add the diced onions and sauté until they become translucent and slightly golden, about 3-4 minutes. Remove the onions from the skillet and set them aside.
5. Add another 1 tablespoon of olive oil to the same skillet. Increase the heat to high and add the sliced mushrooms. Sauté for about 2-3 minutes, stirring frequently, until the mushrooms are browned and their moisture has evaporated.

Step 3: Deglaze the Pan and Make the Sauce

1. Reduce the heat to medium and pour in the ¼ cup white wine (or substitute with broth). Use a wooden spoon to scrape up any browned bits from the bottom of the pan. This step enhances the flavor of the dish.
2. Allow the liquid to cook off completely, which should take about 1-2 minutes.
3. Lower the heat to medium-low and add the cooked onions, drained potatoes, and minced garlic to the pan. Stir everything together.
4. Pour in the 1 cup heavy whipping cream and stir gently to coat all the ingredients.
5. Season with ½ teaspoon black pepper and adjust the salt as needed.
6. Let the sauce simmer for 2-3 minutes, allowing it to thicken slightly.

Step 4: Add Parmesan and Finish the Dish

1. Once the sauce has thickened, add the ¼ cup grated Parmesan cheese and stir to combine. The cheese will melt into the sauce, adding a creamy, salty richness.
2. If you are including cooked chicken or beef, stir it in at this stage and let it warm through for an additional minute.
3. Remove from heat and stir in the ⅓ cup chopped parsley for freshness.

Step 5: Serve and Enjoy

• Serve the dish immediately while warm. The creamy garlic-Parmesan sauce pairs well with a variety of main courses or can be enjoyed on its own.
• Garnish with extra Parmesan and freshly cracked black pepper for added flavor.