
1. Put the cubed salmon, lemon juice and zest into a food processor. Blitz for 2 seconds.
2. Wet the bread in warm water, squeeze it dry and crumble it in. Add salt and pepper and about a third of the Primula tube contents.
3. Blitz again for 6 seconds or until the mix looks even.
4. Toast the cut surfaces of the baps. Squeeze on some Primula then set lettuce on the base of each and some sliced tomato.
5. Divide the fish mix into 4 burger shapes. Squeeze each into a ball; pat out to 1cm thickness.
6. Heat the oil in a large non-stick frying pan until hot. Cook the fish burgers for 3 minutes on very low for the first side; flip and cook for 2 minutes on the second.
7. Set a hot burger on each of 4 garnished baps. Squeeze some Primula onto each. Set lids on or beside and serve while the fish is hot, lettuce crisp, bread still warm.
8. Add some lemon wedges, an extra tomato and ketchup if liked.