Rinse fresh PEI Mussels under tap water. Tap any mussels that are still open and discard any that do not close after being tapped and rinsed. Set aside.
Place in a large saucepan with a small amount of water on high heat. Cover and let steam until shells open (5-7 minutes). Remove fresh PEI Mussel meat from shells, strain and reserve broth.
Add enough hot water to broth to make 4 cups in total.
Melt butter in pot, add onion and sauté until transparent.
Add flour and stir to blend thoroughly with butter.
Gradually add broth and water mixture and bring to a boil.
Add potatoes, simmer until nearly done, add fresh PEI Mussels, and gently stir in hot milk and cream.
Season lightly with salt and pepper. Garnish with bacon strips or a few fresh PEI Mussels.
