Beef stroganoff gets a flavor boost with the help of umami-rich porcini mushrooms.
In a small saucepan, bring the stock and porcini mushrooms to a simmer over high heat. Reduce heat to medium-low and simmer until softened, 2 to 5 minutes.
Bring a large pot of water to a boil for the noodles.
In a large skillet, heat the oil, two turns of the pan, over medium-high. Melt 2 tbsp. butter into the oil. Add the white mushrooms. Cook, stirring often, until browned, about 4 minutes. Add the beef; season with salt, pepper, and the paprika. Cook, breaking up the beef with a spoon, until browned, about 5 minutes. Add the Worcestershire, shallots, and garlic. Cook, stirring often, until the shallots soften, 2 to 3 minutes. Add the brandy. Using a slotted spoon, transfer the porcinis from the stock to a cutting board. Chop and add to the beef. Pour in the stock, leaving the last 2 tbsp. at the bottom of the pan where grit may have settled. Let the Stroganoff simmer over medium-low while cooking the noodles.
Salt the boiling water and add the egg noodles. Cook until about 1 minute shy of the package directions, about 5 minutes. Drain the noodles and return to the pot. Toss with the remaining 2 tbsp. butter, the herbs, and lemon juice; season with salt.
Stir the crème fraîche into the beef. Remove from heat.
Serve the noodles in shallow bowls. Top with the Stroganoff.