Preheat oven to 350. Place vegetables in bowl, cutting up any that need cutting, and toss with about half the pesto.
Smear fish with the rest of the pesto. Place in baking pan and squeeze a few drops lime juice over. If the pan is large and the fish is smaller you can place the veg around it. If you are feeding a crowd and using a larger amount of fish put fish and veg in separate pans.