- 2 leeks
- 2 garlic cloves
- A handful of rosemary, leaves only
- 200g portobello mushrooms
- 500g potatoes
- 1 tbsp wholegrain mustard
- 50g baby leaf spinach
- 50g breadcrumbs
- 1 red onion
- 1 lemon
- 50g rocket
- 2 tbsp olive oil
- Sea salt
- Freshly ground pepper
1. Heat your oven to 200°C/Fan 180°C/Gas 6. Trim the roots and top 3cm off the leeks. Halve them lengthways and finely chop them. Peel the garlic and crush or finely chop them. Finely chop the rosemary leaves. Carefully pull the stalks off the portobello mushrooms. Finely chop the stalks (keep the main mushroom caps for later).
2. Pour 1 tbsp oil into a large frying pan and bring to a medium heat. Slide in the chopped leeks, mushroom stalks, garlic and rosemary. Sprinkle in a little salt and pepper. Fry for 10 mins, stirring occasionally, till softened.
3. Meanwhile, scrub the potatoes and cut them into bite-size chunks. Tip the chopped potatoes into a pan and cover with cold water. Sprinkle in pinch of salt and pepper. Pop on a lid. Bring to the boil, then simmer for 10 mins, or till tender.
4. When the leeks are cooked, stir through 1 tbsp wholegrain mustard and the baby spinach leaves. Place the portobello mushrooms in a roasting tin, gill-side up. Pile the leek and mustard filling onto each mushroom. Scatter the breadcrumbs over the top. Slide the mushrooms into the oven to bake for 20 mins, till golden.
5. While the mushrooms bake, peel the red onion and slice as thinly as possible. Pop it in a bowl. Grate over the lemon zest and squeeze in the juice. Add a small pinch of salt. Scrunch together with your hands andset aside.
6. Check the potatoes – they should be tender and cooked through. Drain the potatoes and allow them to steam dry in the colander for 2 mins. Tip the potatoes into a large bowl. Pour over the quick-pickled red onion and its lemony pickling liquid. Pour over 1 tbsp oil and sprinkle with pepper. Stir to coat everything.
7. Fold the rocket leaves into the potatoes. Scoop the stuffed mushrooms onto plates, pile the potatoes and rocket on the side and serve.