Preheat oven to 300°F.
Heat a large Dutch oven, generously coated with oil, over medium heat. Sweat shallots, leek, carrot, and fennel, stirring occasionally until the vegetables have softened, about 20 minutes.
Add tomatoes, zucchini, garlic, ginger, herbs, wine, and water and bring to a simmer. Turn off heat and add salmon to the pan, gently pushing the salmon into the vegetables.
Put Dutch oven into the preheated oven and roast at 300°F, uncovered, for about 10 minutes.
Cool the dish before gently transferring salmon to a serving platter. Spoon vegetables around onto serving platter with some of the poaching liquid. Discard ginger.
Garnish with fresh chopped herbs and a good glug of oil.