4 servings
Prepare the fish: Heat the oven to 400°F. Finely grate the zest of the lemon into a medium bowl (reserve the zested lemon). Add the pesto and olive oil and stir to combine.
To a large sheet pan, add the collard greens, drained beans, half the pesto mixture, 1/4 cup reserved bean liquid, and salt. Cut the lemon in half and squeeze in 2 tablespoons of juice. Use your hands or two large spoons to combine and spread in an even layer.
Pat the fish fillets dry with paper towels. Season lightly with salt on all sides and use your hands to coat the fillets with the remaining pesto mixture. Arrange the fish fillets on top of the vegetable mixture.
Prepare the bread crumbs: In a small bowl, mix together the panko, garlic, olive oil and salt. Use your hands or a large tablespoon to coat the top of the fish fillets with the bread crumbs, pressing the crumbs down so they stick onto the fish.
Bake until the fish is cooked through and flakes easily with a fork, the greens are tender and the panko topping is golden, 12 to 15 minutes, depending on the thickness of your fish.
Serve immediately with lemon wedges.