Heat oven to 400° F. Heat 1 tablespoon of the oil in a large skillet over medium-high heat.
Season the pork with ½ teaspoon each salt and pepper. Brown, 2 to 3 minutes per side.
Transfer the pork to a baking sheet and roast until cooked through, 5 to 7 minutes.
Meanwhile, add the shallots and 1 tablespoon of the oil to the skillet and cook, stirring often, until soft, 3 to 4 minutes.
Add the wine to the skillet and simmer until reduced by half. Add the cream and simmer until the sauce just thickens. Stir in the mustard.
Top the pork with the sauce and tarragon. Drizzle the frisée with the remaining tablespoon of oil and serve with the lemon wedges.