Heat your oven to 200°C/Fan 180°C/Gas 6. Peel and thinly slice the onions. Peel and crush or finely grate the garlic cloves. Scoop half the garlic into a bowl and set aside for later. Trim the roots and top 3cm from the leeks and rinse under cold water to remove any dirt. Thinly slice the leeks. Pick the thyme leaves off their stalks.

Pour 1 tbsp oil into a large frying pan and bring to a medium heat. Slide in the remaining garlic and the sliced onions and leeks. Sprinkle over the thyme leaves and a generous pinch of salt and pepper. Fry for 6-8 mins, stirring occasionally, till the veg are softened and tender. Stir in 1 tbsp flour and cook for a further 2 mins. Pour in the cream and add 1 tbsp wholegrain mustard and stir to mix.

Spoon the creamy onions and leeks into an oven dish and sprinkle the breadcrumbs over the top. Slide into the oven and roast for 20 mins, till bubbling and golden on top.

While the gratin is baking, cook the pork steaks. Wipe the frying pan clean then add 1 tbsp oil and bring to a medium-high heat. Rub the pork steaks all over with a good pinch of salt and pepper. Carefully lay them in the pan and fry for 5 mins on each side. After the pork has cooked for 10 mins, use tongs to hold the pork steaks upright in the pan and fry the fat for 1 min, till golden. Transfer to a plate to rest.

While the pork rests, cut any tough stems away from the spinach. Reduce the heat under the pan you used to cook the pork to medium. Add the spinach leaves and the remaining chopped garlic. Fry for 2-3 mins, stirring frequently, till wilted.

Pile the garlicky spinach onto a couple of plates and nestle a pork steak on top of each. Serve with generous scoops of the creamy gratin.