Step 1
To a large pot, add the conch, pork, celery, garlic, onion, and 8 cups of water. Bring to a boil, then turn the heat to medium-low, cover the pot, and simmer, stirring occasionally, until the liquid is reduced by about a third, about 3 hours.
Step 2
To a small skillet over medium heat, add the flour and oil and cook, whisking continuously, until the flour turns brown, about 5 minutes. Stir the flour mixture into the stew and continue simmering over medium-low heat until the conch is tender, 1–2 hours.