In a large deep skillet, combine the broth, vinegar, lemon, shallot, garlic, dill, and pepper. Bring the liquid to a gentle simmer over medium heat.
Carefully add the salmon fillets to the skillet, skin-side down. Season with the salt and cover the skillet.
Let the salmon poach in the liquid until cooked to an internal temperature of 145°F, about 5-8 minutes. The exact cooking time will depend on the thickness of your fillets.
Carefully remove the salmon from the poaching liquid using a slotted spoon. Transfer the salmon fillets to serving plates and garnish with fresh dill.
Serve with hollandaise sauce, if desired.
Notes
Storage: Kept in an airtight container in the fridge, the boiled salmon will last for about 3 days. I'd recommend just warming it for a couple of minutes on low heat in the microwave.