Dice the pimientos, celery stalk and onion.
Shred the cheese.
Put the tuna, mayonnaise, pimientos, celery and onion in a food processor and process until smooth but with small pieces of celery and pimientos still discernible.
Transfer the tuna mixture into a bowl.
Stir in the lime (or lemon) juice.
Stir in the shredded cheese.
Add salt, pepper and sugar until the balance that tickles your taste buds is achieved.
Transfer to two large piping bags and keep in the fridge.
To serve, cut off the tip of the piping bag and pipe the tuna and cheese pimiento filling into Tostitos Scoops Tortilla Chips.