In a medium-size pan heat the oil, and saute the onions and chopped garlic, until fragrant. Add the chopped tomatoes, and cook for about 30 minutes at medium heat.
Mix in the cooked chorizo, cloves, cinnamon, thyme and chipotle chiles, add salt, to taste. Set aside.
In a blender or food processor blend the avocado, tomatillos, cilantro, water and salt, until you get a smooth puree. Set aside.
Season the pork tenderloins with salt. In a very hot cast-iron skillet sear the pork for about 4 minutes, turn the pork, and cook on the other side for about 2 minutes or until done. Let rest for about 5 minutes.
On a dinner plate put the avocado-tomatillo salsa. In the center, mound the tomato-chipotle sauce. Slice the pork on a diagonal, and place on top of the tomato sauce and garnish with a sprig of cilantro.