This is the link to the original recipe: Mustardy pork & apples recipe
Ingredients (that I used, the recipe linked to above is slightly different):
Rub the steaks with olive oil and season with salt, pepper, and herbs and spices to taste. I used Montreal steak spice and garlic. Put into heated large frying pan and fry for 2 minutes on each side until golden brown. Remove from pan, add more oil, and fry the onions, potatoes, and sage for five minutes, then add the apples and fry until apples are slightly softened (about three minutes).
Pour in the stock and spoon in the mustard, then return pork to the pan and simmer until the sauce is reduced by about 1/3 and the pork is cooked through (about ten minutes).
It's a relatively easy one dish meal. Clean up is easy and it heats up great for leftovers! I could see adding peppers or squash to the mix as well, although I did refrain from getting too creative the first time out.
For a vegetarian twist, use tofu and veggie stock.