Heat 1 tablespoon of oil in a large deep skillet. Once the oil is hot, add in the smoked sausage medallions, and brown them for a few minutes until they become a deep brown color. Remove the sausage from the pan and set aside.
To the same pan add in the butter, and allow it to melt; add in the onions, and caramelize those in the butter and sausage drippings, about 5-7 minutes. Now add in the garlic, a couple of pinches of salt, the freshly cracked black pepper and the paprika, and stir to combine with the onions. Saute for two more minutes.
Next, add in the sliced potatoes, chicken stock and parsley, and stir to combine. Cover the pan with a lid that and simmer on medium-low heat for about 15 minutes. Then, uncover and allow the potatoes to continue to simmer for 10 more minutes, or until they are tender and the sauce a bit thickened, stirring once or twice during that time.
Finally add the smoked sausage back into the pan, and add a couple more pinches of salt and pepper, if necessary. Serve hot