Melt butter in a large Dutch oven over medium to medium high heat.
Add onion and celery along with a couple large pinches of salt and pepper and cook for 4 minutes, stirring occasionally.
Reduce heat to medium, add garlic and cook for 1 minute, stirring frequently.
Add flour and stir to combine. Cook for another minute, stirring occasionally.
Add half the seafood stock to deglaze the pan and scrape all the yummy bits off the bottom.
Add remaining seafood stock, half and half, and chicken broth.
Then add potatoes, Old Bay seasoning, and bay leaves along with a couple pinches of salt and pepper. Stir until well combined.
Bring to a simmer over medium high heat.
Reduce heat to medium low and simmer gently for 5 minutes, stirring occasionally.
Add most of the crab meat, reserving some for garnish.
Simmer gently for another 5 minutes or until potatoes are fork tender.
Stir in sherry vinegar and season to taste with salt and pepper.
Garnish with chives, parsley, and remaining crab meat and enjoy!
