Preheat oven to 350 degrees F (175 degrees C)
Heat oil in large Dutch oven or enamel baking pot
Sear shanks on all sides and set aside
In the same pot, saute onion and garlic 2 to 3 minutes
Add 2 chillies, tomatoes and chicken stock
Season with cumin, bay leaf, salt and pepper
Boil briefly, then return shanks to pan
Cover and bake in preheated oven for 2 to 2 1/2 hours
Meat should be just ready to fall off the bone
To make the glaze:
Cover 6 chillies with boiling water, and soak for 10 minutes
In a food processor, combine chilies, 1 cup water, honey and orange zest
Process until smooth; set aside
To make the topping:
In a small bowl, mix together yogurt, cilantro and salt
Cover, and refrigerate
When the shanks are done, remove them from the Dutch oven, and place them into an oiled roasting pan
Increase oven temperature to 400 degrees F (200 degrees C)
Spread glaze over shanks and return to oven until light crust forms, 6 to 10 minutes
Serve on large plates surrounded by tomato base and topped with the refreshing yogurt mixture