Preheat grill to medium-high and coat with oil.
Season both sides of each salmon fillet with salt and pepper and place on the grill
. Grill until the center is still slightly pink, 6 to 8 minutes total, rotating fish
90 degrees halfway during cooking on each side to obtain hash
marks. Remove from the grill.
Meanwhile, make the pear butter sauce: In a medium saucepan
, combine the diced pears, sugar, and hard cider
. Cook over medium-high heat until the pears are translucent, about 5 minutes. Add the cream and cook until reduced by half, about 6 minutes. Add the butter several pieces at a time, whisking constantly to blend
, and removing from the heat periodically to prevent the sauce from breaking. Add 1/4 teaspoon salt and 1/8 teaspoon white pepper and whisk
to blend. Remove from the heat and cover to keep warm until ready to serve, stirring occasionally. (Do not allow sauce to boil or it will separate.)
Place the salmon on the plate with the roasted potatoes, drizzle
the pear butter over the salmon and serve immediately.