Cut the leek into 1cm thick rounds.
Finely chop the garlic, then cut the bell pepper into slices or chunks.
Heat the oil in a casserole dish and gently sauté the leek for about 5-8 minutes until tender.
Add the pepper, tomatoes (on the vine) and scatter the garlic around them.
Pour over the wine, then put the lid on and cook for 5 minutes until tender.
Meanwhile cut the haddock into 2-3 pieces.
Place the fish on top of the tomatoes, then drizzle with lemon juice. Season with salt and pepper, then dust with paprika and scatter the dill on top.
Put the lid on and gently steam for about 5-8 minutes, depending on the thickness of the fish.
Serve warm.