Combine hot water with bouillon paste or cubes and combine. Set aside.
In a wide deep skillet or dutch oven over medium heat, add 1 tablespoon neutral vegetable oil. Cut Impossible Beef Made From Plants into chunks or cubes and place them in the hot skillet. Season with sea salt and ground pepper to taste. Brown for 3 to 4 minutes then toss and brown the other sides about another 3 to 4 minutes. Once cooked through remove the Impossible Beefbpieces from the skillet into another dish and set aside.
With the skillet still over medium heat add 2 tablespoons butter and the sliced onion and cook, stirring occasionally to scrape up the brown bits in the pan, until the onions are softened, 4 to 5 minutes. Add cremini mushrooms, shiitakes, thyme, and remaining butter and cook, stirring occasionally scraping up any brown bits until the mushrooms have released some liquid and are starting to crisp, 5 to 6 minutes. Stir in the garlic, Worcestershire, and dijon and cook for about 1 to 2 minutes.
Add pasta and all the stock, and stir to combine. Cover with a lid and bring to a boil cooking for 8 to 9 minutes or until pasta is al dente.
Lower heat to a simmer and stir in sour cream and parsley until well combined. Add the Impossible beef pieces back in and stir to combine. Serve immediately hand garnish with fresh ground black pepper to taste and more parsley.