Place the potatoes and carrots in a pot, cover with a generous amount of cold water and then boil until firm tender. Add the broccoli and cook 2 minutes more. Drain the vegetables well, cool in cold water and then drain well again. Preheat the oven to 375 degrees F.
Butter a 9 by 13 inch baking pan and set in the salmon. Surround the salmon with the vegetables; season with salt and pepper. Combine the stock, garlic, lemon juice and dill in a bowl. Drizzle over the salmon and vegetables. Cover and bake 15 minutes, or until the fish is just cooked through.