Peel sweet potato and cut into medium chunks. Cover with cold water, season with salt, cook for 8–12 minutes once boiling — pierce with a fork to check that it is tender.

Finely dice half the lemon, cut remaining half into wedges, and set aside for serving.

Roughly chop parsley and finely chop garlic.

Heat vegetable oil over medium-low heat and cook garlic, stirring, for 2–3 minutes without letting it brown.

Add sauce spice blend and diced lemon, mixing well.

Carefully pour strained tomatoes and add 100 ml water per each serving into frying pan.

Season generously with salt, bring to a boil, reduce heat to medium-low, and nestle fish into sauce.

Cover with a lid and cook for 6 minutes.

Drain cooked sweet potato and mash with a spoonful of your favorite vegetable oil.

If you prefer silky texture, you might want to blitz with an immersion blender. Taste for salt.

Once fish is cooked through, check the consistency of tomato sauce — loosen with a splash of water or let it simmer a bit more to reduce if needed.

Taste for salt and acidity (if it tastes too tart, stir in a pinch of sugar or a teaspoon of honey).

Scatter with parsley and serve with lemon wedges.