Peel the lemon and orange zest in wide strips, and put them in a small pan with 100g sugar and one tablespoon of water. Simmer over very low heat until the sugar has melted and turned a light golden colour. Stir in the hazelnuts and immediately spread the mixture onto parchment paper. Leave to cool. Break the praline into pieces and pulse these in a food processor to get a fine, crisp crumb. Preheat the oven to 350f. Put the rhubarb slices in an oven dish. In a pot, bring to a boil the remaining 100g of sugar, the ginger, the wine, and 300mls water. Pour this over the rhubarb and place the dish in the oven for 15-20 minutes, until the rhubarb is just tender but still firm. Transfer the rhubarb pieces to a container to cool. Whisk the olive oil with the juice of the lemon and half of the orange. Discarding any stringy outer leaves and the core, cut the fennel bulb in quarters, then into thin slices. Toss the fennel with the watercress, goat’s cheese and a little of the dressing. Divide between four plates and place some of the rhubarb in and around each portion. Drizzle a little more dressing over, and sprinkle some praline on top.