In a large bowl, combine the cumin, coriander, sugar, ancho powder, cinnamon, garlic powder, and pepper. Mix the spices well with a wooden spoon. Season the pork ribs on both sides with salt, then start rubbing the spice mixture evenly on both sides to coat all the surface meat. Place in refrigerator, cover, and allow to sit overnight.
Preheat oven to 300 degrees F.
Wrap the pork ribs tightly in plastic, then place in shallow baking dish with 1-inch of water and place the pan in the oven for 1 hour and 30 minutes. Remove the ribs from the plastic wrap and set aside.
While the ribs are cooking, in a large sauce pot, add 1 tablespoon oil and heat over medium high heat. When the oil has begun to smoke, add the onion, ginger, lemongrass, garlic, and jalapeno. Start cooking until the onion becomes translucent, about 7 minutes. Then, add the honey, chicken stock, and tamarind. Simmer for 20 minutes then puree in a blender until smooth. Season with salt and pepper and strain through a medium fine strainer. Set aside.
To make the dressing for Chayote Slaw: In a small sauce pot, combine the honey, pepper flakes, and vinegar. Cook 10 minutes until the mixture is reduced by half. Set aside to cool in a large mixing bowl. When the mixture is cool, add the chayote, red onion, mango, cilantro, tomato, olive oil, and lime juice. Mix well and set aside.
To finish the dish: On a hot well oiled grill, add the cooked pork ribs and start to cook on one side 5 minutes making sure to baste the other side with tamarind glaze. Then, flip the ribs over and baste this side for 5 minutes. Repeat this process three times until a nice crust has formed. Remove and cut between each bone and serve on a large platter with the Chayote Mango Slaw and a side bowl of the tamarind sauce.