Spoon the tilapia filling evenly down the center of the salmon
. Lifting the plastic from one of the long edges, gently roll the salmon
around the tilapia into a sausage
shape. Tighten the plastic as much as possible without squeezing the salmon
out the ends. Twist the ends of the plastic and secure with string. Wrap the salmon
roll in another layer of plastic wrap and secure the ends with more string.