Roast the peppers on top of the stove, on the grill, or under the broiler. Remove, transfer to a medium-size bowl, cover with plastic wrap, and let steam for 10 minutes. When cool enough to handle, peel and discard the skins. Return to bowl, and add olive oil, thyme, and garlic. Let marinate for 30 to 45 minutes.
Meanwhile, combine 1 quart water, white wine, onion, lemon, dill, peppercorns, and salt in a shallow pot. Bring to a boil, and reduce the heat to simmer. Add the salmon, and poach 8 to 10 minutes. Remove from the court bouillon, and set aside. The salmon may be chilled at this point.
On a very large platter, arrange the salmon and peppers in a decorative fashion, reserving the flavored oil. Between the salmon and peppers, place small bunches of wax beans and haricots verts. Evenly distribute the tomatoes on top and in between. Sprinkle with capers, and drizzle with the reserved oil from the peppers. Top with fennel, thyme, parsley, and balsamic vinegar. Season, to taste, with salt and pepper.