In a small bowl, stir together parsley, thyme, rosemary, garlic, mustard, salt, pepper and olive oil until well combined. Spread on both sides of the lamb chops, cover and refrigerate at least 30 minutes or up to 4 hours. Brush most of the marinade off of the chops and discard.
Heat the oven to 375°F. Heat a large cast iron skillet over medium heat. Add 1 tablespoon of the high heat oil, and cook shallot 1 to 2 minutes or until beginning to brown, stirring frequently. Add mushrooms, cook an additional 3 to 4 minutes or until softened, stirring frequently. Remove the shallots and mushrooms from pan to a bowl, set aside.
Heat the remaining 1 tablespoon oil in the same skillet over high heat. Add lamb; cook until browned, about 1 to 2 minutes per side. Add the shallot, mushrooms and tomatoes back into the skillet and transfer to the oven. Roast 5 to 7 minutes or until desired doneness.