Preheat the grill to medium-high. Lightly coat with oil.
Season both sides of the lamb chops with salt and pepper. Grill until medium rare (12o degrees F), about 3 minutes per side.
Serve with the tart cherry sauce.
The Sauce:
In a medium saucepan, stir together the tart cherries, red wine, orange juice, maple syrup and rosemary. Bring to a boil and cook for 2 minutes, stirring frequently.
Reduce heat to medium-low and simmer for about 8 minutes. Whisk in the flour and cook for 2 additional minutes.