Mitch Tonks's Pollack with Young Greens

Preheat the oven to 200°C (Gas Mark 6). Place an oven-proof pan on a medium-high heat and add a good splash of olive oil. Season the fillets with salt and pepper, then place them in the pan, flesh-side down. Cook for 3-4 minutes until golden, then turn the fish over and place the pan in the hot oven for a further 2-3 minutes.

Meanwhile, steam the cabbage or spinach over a pan of boiling water until wilted, then take off the heat. In a small pan, melt the butter, whisk in the mustard until properly emulsified, then add the remaining ingredients and mix well. Toss the wilted greens in the sauce to coat, then season with plenty of black pepper. Serve the greens alongside the fish and spoon over any remaining sauce.