Preheat the oven to Gas Mark 6, 200°C, 400°F. Mix the fresh thyme and breadcrumbs with the olive oil.
Pop the fillets on a lightly oiled roasting tray. Spread a teaspoon of the pesto on top of each fillet. Then divide the herby breadcrumb mix between the 2 fillets, pressing down lightly on top.
Bake for 15-20mins until the fish is cooked through. Serve with some roasted tomatoes.
Kids love the pesto on the cod, but for a different, grown-up version, try using horseradish instead
Fay's Family Food by Fay Ripley, text © Fay Ripley 2009, photography © David Munns 2009, published by Michael Joseph is available online at www.tesco.com