Place cleaned trout fillets in the container of a food processor fitted with steel blade and pulse a few times, until well chopped. (You can also do this by hand with a sharp knife). Transfer trout to a mixing bowl. Fold in onions and chives and stir. Add mayonnaise and stir to combine. Add lemon juice, pecans and salt and pepper to taste. Stir well, cover and refrigerate.
Packaging tip: Pack pate into a pretty glass bowl or crock and cover with plastic wrap. Tape a white card to the top of bowl and label, including serving suggestions. Tie a moss green bow around bowl and present along with a bag full of toasted bread rounds and a jar of French cornichons.