Trim the stem ends of the peperoncini at an angle and, wearing rubber gloves, discard the seeds and ribs. Let the peperoncini drain on paper towels. In a bowl cream the cream cheese with the butter until the mixture is smooth, add the dill, the sallot, a nd the lemon juice, and combine the mixture well. Stir in the salmon and salt and pepper well. Transfer the mixture to a pastry bag fitted with a 1/2-inch decorative or plain tip, and pipe the smoked slamon and dill cream into the peperoncini. The pepero ncini may be prepared 1 day in advance and kept covered and chilled.