Prepare your veggies: Dice the onions, chop the garlic, and cut the portobellos into chunky cubes for a meaty bite.
In a large sauté pan, melt 1 tablespoon of butter over medium-high heat.
Add the onions and sauté for 5 minutes, stirring occasionally.
Add the remaining 2 tablespoons of butter, and the garlic and mushrooms to the pan. Stir to combine and continue sautéing until the mushrooms are cooked and tender.
Pour in the white wine, using a wooden spoon to deglaze the pan and scrape off any brown bits from the bottom. Allow the sauce to simmer for about 5 minutes so the alcohol evaporates.
Add the spices, salt, paprika & thyme.
In a separate bowl, whisk together the vegetable stock, Worcestershire sauce, and flour until smooth.
Add the vegetable stock mixture to the pan. Allow the mixture to simmer for an additional 5 minutes, stirring occasionally, until slightly thickened.
Incorporate the Greek yogurt (or sour cream) evenly into the sauce.
Taste the sauce and season with a pinch of salt and pepper as needed.
Serve hot over rice noodles or white rice.
Toppings: Fresh parsley, parmesan cheese, black pepper
