Toss the brussels sprouts with enough olive oil to coat, a genereous pinch of salt and pepper to taste.
Put the sprouts on a baking sheet pan in the preheated oven for 15 minutes.
Meamwhile, in a small saute pan, gently simmer the balsamic vinegar with the honey until the mixture has reduced and is slightly thickened, 3-5 minutes. Set aside.
After 15 minutes, removed the Brussels sprouts from the oven, and test with a paring knife. If the Brussels sprouts are not sufficiently charred to tender, return to the oven for 5 minutes. If they appear to be charring too much, reduce the oven to 400 and continue roasting until they are knife tender.
When the Brussels sprouts are finished cooking, remove from the oven, transfer to a bowl, aned add the pistachios and apple slices.
Pour the reduce balsame mixture into the bowl and toss to coat evenly.
Transfer mixture to serving platter and top with a dollop of creme fraiche. Add more salt and creme fraiche if desired.