Heat the oven to 200°C (400°F). Cut 4 large sheets of heavy-duty foil, about 40 cm each, and lay them on a work surface.
Divide the green beans between the foil sheets, making a small bed in the centre of each one. Drizzle with the olive oil and season with half the salt and pepper.
Place a cod fillet on top of the green beans on each sheet. Season the fish with the remaining salt and pepper, then spread 1 tablespoon of pesto over each fillet.
Scatter the cherry tomatoes and sliced garlic around the fish, and lay 2 lemon slices on top of each fillet.
Bring the long edges of the foil together above the fish and fold them over twice to seal, then fold the short ends in twice so each packet is tightly closed. Leave a little air inside so the fish can steam.
Place the packets on the rimmed baking sheet and bake for 18–20 minutes, until the cod flakes easily with a fork and reaches 63°C (145°F) in the centre.
Let the packets rest for 2 minutes, then open them carefully — the steam is hot — and serve straight from the foil or slide the contents onto plates, scattered with fresh basil.
Notes
Seal packets tightly so the fish steams. Rest 2 minutes before opening — the steam is hot. Keeps 2 days refrigerated.
Keyword cod, dinner, foil packets, high protein, pesto cod, thanksgiving