Celeriac steaks with tonnato sauce & pumpkin seed salsa

First make the tonnato sauce. Put 6 tbsp oil and the whole garlic cloves in a small saucepan. Set over a medium-low heat and cook gently for about 5 minutes until the garlic is golden and soft. Use a slotted spoon to transfer the cloves to a small food processor, adding the lemon juice, 1½ tsp vinegar, the tuna, anchovies, mustard, egg yolk, ½ the capers and ½ the parsley. Whizz to form a smooth paste, then, with the machine still running, slowly pour in the warm, garlic-infused oil from the pan. Keep the machine running until it reaches a mayonnaise-like consistency. Transfer to a bowl and set aside until ready to serve.

For the salsa, mix the pumpkin seeds, remaining parsley, lemon zest and 2 tsp vinegar in a bowl with 1 tbsp oil. Heat another 1 tbsp oil in a small pan over a high heat, then fry the remaining capers for about 90 seconds until crispy. Using a slotted spoon, transfer to a plate lined with kitchen paper and set aside. Once cool, stir into the salsa.

Preheat the oven to 200oC, gas mark 6. Cut each slice of celeriac in two, so that each forms two half-moons. Add 2 tbsp oil to a large, ovenproof frying pan (about 24cm diameter) over a medium heat. Stir in the salt, then add the celeriac slices, turning to coat. Fry for 12-15 minutes, turning halfway, until golden brown on both sides. Transfer the pan to the oven and cook for 10 minutes until the celeriac is tender. To serve, divide the tonnato among four plates and put 2-3 half-moons of celeriac on top. Spoon over the salsa and serve with lemon wedges on the side.