Sauté the Aromatics — In a large pot, melt butter, or heat oil over medium heat. Sauté chopped onion, celery and garlic until softened and the air is fragrant.

Make the Base – Add the flour and stir to coat the vegetables thoroughly, cooking for 1–2 minutes to remove any raw taste of the flour. Add the vinegar, and stir to deglaze the pot.

Simmer the Broth – Pour in fish broth, chicken broth, bay leaf, Old Bay seasoning, and diced potatoes. Bring to a boil, then lower the heat and simmer until the potatoes are tender.

Make It Creamy – Lower the heat to low and add in the half & half in a steady stream while stirring. Allow the soup to warm through but do not boil, to prevent curdling.

Add the Crab — Add the crab meat gently at the end, then let it warm through for a few minutes, but not long enough to overcook, so that it remains flaky.

Finish & Serve – Remove the bay leaf, taste and adjust seasoning if necessary. Just before serving, sprinkle with fresh parsley or another dash of Old Bay seasoning. Enjoy!