Mix the mustard, pepper, thyme, oregano, rosemary, paprika, sliced garlic, cardamom, and maple syrup together in a bowl. Coat the lamb chops evenly.
Add salt now if marinating for 30–60 minutes; if marinating for several hours or overnight, add salt right before cooking.
Heat a skillet over high heat. Shake off excess marinade and garlic, then sear the lamb chops for 3 minutes per side for medium. Set meat aside on a plate.
Lower heat to medium, melt the first 1 tbsp of butter in the pan drippings, and sauté onion, garlic, and leftover marinade for 1–2 minutes.
Deglaze the hot skillet with red port wine, scraping up the bottom bits until reduced by half.
Reduce heat to low/off, stir in the light cream, and another tbsp of butter and return the lamb chops to the pan, coat in the sauce, and serve hot!