5 large potatoes, peeled and diced (about 3 cm)

Salt and pepper, to taste

2 free-range eggs (optional)

2 handfuls spinach (about 200 g baby spinach)

1 onion, finely chopped

1 carrot, diced small or grated

1–2 celery stalks, finely diced

Extra virgin olive oil, for frying

250 ml single cream

1 cup grated mature Cheddar cheese or Parmesan (or a mix)

1 tbsp lemon juice

2 tsp Dijon mustard or English mustard

1 large handful flat-leaf parsley, finely chopped

500–650 g smoked haddock (or cod, hake, salmon, or mixed fish), cut into chunks

2 tbsp butter (or more for richer mash)

¼ tsp nutmeg (optional, for mash)