Mustard & Herb Baked Fish in Foil with Roasted Vegetables

Use a firm, flaky fish that holds its shape. Cod, haddock, hake, or halibut are perfect. Avoid delicate, thin fillets like sole or plaice, as they can overcook quickly. Thicker fillets (around 2-3cm) are ideal for the 30-minute bake.

Absolutely. Choose vegetables that roast well in the same timeframe. Zucchini (courgette), thinly sliced fennel, red onion wedges, or asparagus spears are excellent. Avoid very hard roots like potatoes or carrots unless pre-cooked, as they won’t soften in time. I have shared another similar recipe with Mackerel and Summer Veggies you might want to check out.

Wholegrain mustard provides texture and a mild, aromatic tang. You can substitute with Dijon mustard for a smoother, sharper sauce. Avoid overly sweet or flavoured mustards. The mustard is a key flavour component, so don’t skip it.

After 30 minutes in a properly sealed parcel, a typical 2cm-thick fillet should be done. The most reliable method is to carefully open one parcel and check: the fish should be opaque throughout and flake easily with a fork. If unsure, you can use a meat thermometer; it should read about 55°C (131°F) for medium.

Yes, you can assemble the parcels completely up to 4 hours in advance. Store them in the refrigerator on the baking tray. Let them sit at room temperature for 15-20 minutes before baking, and you may need to add 2-3 minutes to the cooking time.

Yes, it’s an excellent method. Prepare the parcels as instructed. Place them on a preheated medium-high grill (about 200°C). Cook for 15-20 minutes, depending on the heat of your grill, until the fish is cooked through. The foil will puff up.

This happens if your vegetables (like mushrooms, tomatoes, zucchini) release a lot of moisture. Ensure you are using the full 30-minute cook time to allow the steam to evaporate and concentrate flavours. You can also slightly pat dry sliced mushrooms before assembling.

The recipe is naturally both dairy-free and gluten-free. Just ensure your mustard and any stock or added seasonings are certified gluten-free if required.

Fresh herbs like dill, tarragon, or thyme are wonderful with fish. If using dried, thyme, herbes de Provence, or a simple Italian seasoning blend work well. Add dried herbs to the vegetables; if using fresh, add them on top of the fish before sealing the parcel.

Serve each person their own unopened parcel at the table for a fun presentation, or plate it for them. This dish is a complete meal. For a heartier option, serve with crusty bread to soak up the juices, or a side of simple buttered rice or couscous.