Heat the butter and oil In a heavy bottomed large pot or Dutch oven. Add the ground meat, break it up with a wooden spoon or spatula, and allow it to brown as best as possible.

Meanwhile, dice the onions and add them to the pot along with the salt, pepper, and garlic.

Slice the mushrooms and add them to the pot. Allow the mushrooms, onions, and meat to cook for 4-5 minutes or until the onions and mushrooms soften.

Crumble in the stock cube, add the mustard, Worcestershire sauce, and boiling water, and stir well to combine.

Add the noodles and stir everything together. Crank up the heat to max until the water comes to a boil, then reduce the heat to medium-low, cover with a lid, and allow to cook, stirring occasionally, according to the package instructions on the pasta.

Once the pasta is done, the mixture should still be quite liquidy, but the pasta will have absorbed a lot fo the liquid. Remove the pot from the heat, stir in the sour cream, and allow the pasta to sit, covered, for 5 minutes.

Meanwhile, chop the herbs (parsley or dill). After 5 minutes, stir in the fresh herbs and serve.