2) When it lifts cleanly, rotate about 45 degrees from the original position (don't turn it over). Cook about another 2 minutes, until griddle marks appear. Flip the fish and repeat this process for marking the fish on the other side, another 3 to 4 minutes.
For the compote:
1) Toast the pine nuts in the olive oil in a pan over high heat, swirling the pan until the nuts are golden, about 3 minutes. Transfer the nuts to a dish with a slotted spoon and set aside, leaving the oil behind in the pan.
2) Add the onion, fennel, garlic, lemon peel, 1.25 tsp salt, fennel seeds, saffron and black pepper to taste and cook until the onion and fennel are slightly wilted, about 2 minutes.
3) Add the sultanas and cook, stirring occasionally, until the mixture browns and softens, about 5 minutes. Stir in 60ml water, the pine nuts and the parsley.
4) Cook, stirring occasionally, until the liquid reduces and the compote thickens, about 1 minute more. Set aside.
5) Cut the tomato into thick slices, season with salt and black pepper to taste, and divide among 4 plates. Place the fish on top of the tomato slices, spoon some compote over, and serve with a wedge of lemon.