Debora Robertson's Updated Sunday Lunch: Roasted Whole Sea Bass Recipe

Many people are intimidated by cooking fish, but it's the first thing they order when they go to a restaurant. It's understandable. It's not cheap, and you can overcook it easily and it usually needs to be cooked at the last minute. But cooking a whole fish takes those pressures away and it's really wonderful when you put it on the table. If you have a lot of people, you can easily make two trays. You can also do all the preparation a few hours in advance and start cooking about 45 minutes before you want to eat. Fish also tastes best when cooked on the bone.

Serves 4-6, depending on what else you are serving

Put the oil in a small saucepan with the lemon zest and fennel seeds. Heat gently, without simmering, for 5 minutes, then remove from the heat and leave to cool.

Preheat the oven to 180 C convection heat/thermostat 6.

< p class="dcr-8zipgp">While the oil cools, prepare the vegetables. Peel the potatoes and slice them thinly. If you're the mandolin type, use it. I'm not the mandolin type and after a long bloody history of pretending that I am, I hope you don't mind if I just sit here quietly with a sharp knife and cutting board, and do my best I can get small, skinny potato slices without having to ruin Sunday lunch rushing to A&E. I once went to lunch on Sunday with our friends Fred and Kay, and Fred cut his hand on a can of foie gras. He ran off to A&E, got stitched up, and was back before the main course was served, and despite his admirable composure, that's not ideal.

Quarter the fennel, remove the hard pit, then thinly slice the quarters (see above). If your fennel has leaves, save some to put inside the roasted fish. Remove the leaves from 4-5 sprigs of thyme.

Brush a little seasoned oil all over the inside of a roasting pan or casserole dish ceramic bowl large enough to hold the fish. Put the potatoes, fennel and shallots in the pan with the thyme leaves, 4 sprigs of tarragon and 3 bay leaves, and drizzle about 3 tablespoons of oil (retain the strip of lemon zest, but let some of the fennel seeds fall into it).

Pour in the lemon juice and season with a teaspoon of salt and pepper. Stir well, then pat everything in an even layer. Cover tightly with foil and place in oven to roast for about 30-40 minutes, removing once to turn everything over before covering again and returning to oven. When all the vegetables are tender, remove the foil and whip the oven to 200C fan/thermostat 7. Make sure it's up to temperature before putting the fish in.

< p class="dcr-8zipgp" >Prepare the fish by cutting 3 or 4 diagonal slashes almost to the bone on both sides. Place the fish on top of the vegetables and brush with oil, inside the cavity and in the cuts, and all over the skin. Put the lemon zest strips, remaining thyme sprigs, tarragon sprig, and bay leaf inside the fish, along with some fennel seeds and any fennel leaves you have. Season the fish with salt and pepper and return the entire tray, uncovered, to the very hot oven.

Roast for 20 minutes, until the fish is tender is just done - to test this, press a small, sharp knife into one of the cuts and if you can gently scrape some of the flesh off the bone without resistance, it's done. Rest for 5 minutes before serving (but make sure the plates are warmed), with a little more fruity olive oil dripping over the top.

From Notes of a Small Kitchen Island by Debora Robertson (Michael Joseph, £26)