Seafood Gumbo

1 kilo shrimps
1 large onion, peeled, chopped (save skin)
4 liters water
1 kilo okra, sliced crosswise into 1/4-inch pieces oil for frying okra
1 cup all purpose flour
1/2 cup oil (use olive oil for healtier version)
1 large bell pepper, chopped
3 stalks celery, chopped
5 pcs or about 1 kilo medium sized crab (alimasag), cut into halves
500g canned whole tomatoes, chopped coarsely (if using fresh, peel and remove seeds)
Salt & pepper to taste
1 clove garlic, crushed and peeled
2 tablespoon thyme
1 bay leaf
1 bunch spring onions, chopped

Procedure:

Peel shrimps, saving the peels and heads.
In the stockpot, place the shrimp peels and heads with the onion skin. Pour in 4 liters of water and boil for 20 minutes. Strain and set aside this shrimp stock.
Fry okra in very hot oil until lightly brown. Drain.
Make a dark roux with the flour and olive oil, mixing the two while cooking until the roux achieves the color of milk chocolate brown.
Add the onions, stirring together until the roux darkens to a bittersweet chocolate brown.
Add the chopped the celery and bell pepper. Saute for 5 mins.
Then add the crab, tomatoes, okra, salt, pepper, garlic, thyme, bay leaf and shrimp stock. simmer for 45 minutes.