Rotisserie celeriac with chimichurri

The cook

1. 01

   Step 1SORT THE FIRE

   Set up a BBQ with a rotisserie attachment. Bank lit briquettes on two opposite sides, leaving a clear channel beneath the spit, and put a drip tray in that gap. Fit the lid and settle the cooking temperature at 190°C. You're roasting with steady surrounding heat, not blasting the underside.

2. 02

   Step 2TRIM AND SEASON

   Scrub the celeriac, then trim away the roots and peel off the tough skin with a sharp knife. Cut out any muddy crevices and pat dry. Keep it as round as possible so it turns evenly. Mix the olive oil, salt, smoked paprika and pepper, then rub all over.

3. 03

   Step 3GET IT SPINNING

   With the spit off the BBQ and the celeriac held securely on a board, carefully push the rod through its centre, keeping your hands clear of the point. Drive the forks firmly into both ends and tighten them. Fit the spit, switch on the motor and check that the celeriac rotates without slipping or catching the tray.

4. 04

   Step 4ROAST UNTIL GOLDEN

   Close the lid and cook at around 190°C for 2–2½ hours, allowing up to 3 hours for a particularly thick celeriac. Check the fire and fork fixings every 40–45 minutes, stopping the motor before making adjustments. Keep the heat steady and top up with lit briquettes as needed. If the outside darkens too quickly, reduce the temperature to 170–180°C.

5. 05

   Step 5CHOP THE CHIMICHURRI

   About 30 minutes before serving, stir the chopped parsley, garlic, chilli and oregano together with the vinegar and olive oil. Season with salt and pepper, then leave for 20–30 minutes. Give it another stir and taste. It should be sharp, garlicky and lively enough to wake up the whole plate.

6. 06

   Step 6CHECK THE CENTRE

   Start checking tenderness after 2 hours. Stop the motor and push a thin skewer into the thickest part, away from the metal rod. It should slide right through with very little resistance. A golden outside isn't enough; if the centre still feels firm, keep cooking and check every 15–20 minutes.

7. 07

   Step 7REST AND CARVE

   Wearing heatproof gloves, lift the spit onto a sturdy heatproof tray. Carefully loosen the forks and slide out the hot rod. Rest the celeriac for 10 minutes, then carve into thick wedges. Spoon over the chimichurri, getting plenty into the cut faces, and bring the remaining sauce to the table.