Cook and stir onions and green pepper in margarine in 3-quart saucepan until onion is tender, about 3 minutes.
Add collard greens and water.
Heat to boiling; separate greens with fork.
Cover and simmer 5 minutes.
Cut fish into strips, 4 x 3/4 inches each; add to vegetables.
Sprinkle with salt, paprika and pepper.
Heat to boiling; reduce heat.
Cover and simmer until fish flakes easily with fork, about 5 minutes.
Garnish with lemon wedges if desired.