Joan's Secret Deli-Style Tuna Fish salad

1 can (6 oz) top quality solid packed white albacore tuna in water-no substitute for albacore
1 Tbs top quality mayonnaise (not salad dresssing) to start
1 Tbs. plain renedered pure schmaltz (approx) to start
a few tsp of finely shredded carrot
a few tsp of finelly shredded mild white onion
pinch salt, pinch pepper

Drain tuna and place in mixing bowl. Break up and mash tuna with fork to remove clumps and make a spreadable consistency. Mix in carrot and onion. Mix in the mayo. Then add and mix in enough schmaltz until tuna achieves a rich taste,

The important part:
Tuna should neither be flavored with either too much mayo or schmaltz. That is another part of the secret I think. You shouldn't be aware of any blatant schmaltz taste in the tuna. Salt carefully as the tuna should not have a salty taste either.

http://www.cyber-kitchen.com/rfcj/ROSH_HASHANAH/Tuna_Salad_Joans_Secret_Deli_Style_-_meat.html