Begin by heating a large pot over medium heat and adding a drizzle of oil. Once hot, toss in minced garlic and sauté for about 1–2 minutes until golden and fragrant.

Add diced potatoes along with seafood stock to the pot. Increase the heat to bring the mixture to a gentle boil, then reduce to a simmer. Cook the potatoes until they are fork-tender, about 15 minutes.

Once the potatoes are tender, carefully stir in the white fish, shrimp, scallops, and mussels. Cook together for approximately 5 to 7 minutes, until the seafood is just cooked through.

Reduce the heat to low and pour in the heavy cream and whole milk, stirring gently to combine. For a thicker consistency, mash a few potato pieces against the side of the pot.

Taste and adjust the seasoning with salt and pepper as needed. Optionally, add a splash of white wine for extra flavor.

Ladle the chowder into bowls, ensuring each serving has an ample amount of seafood and potatoes. Discard any mussels that did not open during cooking. Serve immediately.