Place the pork roast and onion in a crock pot.

Cover with water.

Cook on low heat for at least 12 hours (overnight).

Turn off the crock pot and let it cool for about 6 hours.

Strain the meat through a colander, saving the juice.

Discard the cooked onion.

Separate the meat from the fat and place the meat in a large soup pan.

Add the juice from the crock pot to the soup pan.

Add 4 oz of diced green chilis (adjust amount based on desired hotness).

Add 4 oz of diced jalapenos (adjust amount based on desired hotness).

Add one 16 oz can of diced stewed tomatoes.

Bring the mixture to a boil.

In a jar, combine 1 cup of water with 4 tablespoons of flour and shake well.

Stir the flour mixture into the chili.

Let the chili thicken.

Serve hot with tortillas.