Preheat the oven to 425°F.
Slice off a lengthwise piece of each jalapeño then, using a small spoon or paring knife, scrape the seeds out of each pepper to make little jalapeño canoes. Chop the tops finely and add to a mixing bowl with the cream cheese, Manchego, green olives, parsley, salt and freshly ground black pepper. Use a small spoon to fill the canoes or transfer the mixture to a re-sealable plastic bag, snip off the end and squeeze the mixture into the hulls of your jalapeño canoes.
Arrange the peppers on cookie sheet, transfer to the oven and roast for 15 minutes.