In a large skillet, melt 2 tablespoons of unsalted butter over medium heat. As the butter heats, keep an eye out for it to become foamy and start to bubble, which takes about 1-2 minutes.

Add 1 diced medium onion to the skillet, stirring frequently for about 5 minutes until it softens and turns golden brown.

Next, add 10 ounces of sliced cremini or button mushrooms to the skillet and sauté for about 8 minutes, stirring occasionally, until the mushrooms are tender and most of their liquid has evaporated.

Stir in 2 minced garlic cloves, 1 tablespoon of sweet paprika, and 1 teaspoon of smoked paprika. Continue cooking for about 30 seconds.

Sprinkle 2 tablespoons of all-purpose flour over the mixture, stirring well. Gradually pour in 1 cup of vegetable broth while mixing continuously.

Bring the sauce to a gentle simmer by reducing the heat slightly. Let it cook for about 5 minutes, stirring occasionally until it thickens to a velvety consistency.

Lower the heat and gently stir in ¾ cup of sour cream until completely combined. Avoid boiling the sauce after adding the sour cream.

Taste and adjust seasoning with salt and pepper. Serve immediately over cooked wide egg noodles or alongside crusty bread.