Cut the fish fillets into individual portions of 4 to 6 oz (100 to 400 g) each.
Cut the carrots and fennel into batonnet, about 2 inches (5 cm) long. Cook them separately until they are cooked through but still crisp.
Trim the ends of the snow peas. Blanch them for about a minute in boiling water, until they are just cooked but still crisp.
Reduce the vinegar by half over moderate heat. Remove from the heat and add the remaining ingredients, seasoning to taste with salt.
Cooking/Finishing:
Season the fish fillets with salt and pepper and brush them with olive oil. Grill them on both sides until they are done.
Heat the mixture of vinegar, oil, and seasonings (from step 4 of mise en place) until simmering. Add the carrots, fennel, and peas and simmer just until the vegetables are heated.
Presentation:
For each portion, place a portion of fish skin side up in the center of the plate.
Spoon the vegetable mixture all around the fish, so that the solids are evenly and randomly distributed.