Heat the olive oil in a Dutch oven or large pot over medium-high heat. Season the pork with salt and pepper to taste, then place into the hot oil. Cook until golden brown on all sides, about 7 minutes. Once browned, remove the pork and set aside. Reduce heat to medium, and stir in the onion and garlic. Cook and stir until the onion has softened and turned translucent, about 5 minutes.
Return the pork to the pot, and stir in the green chiles, diced tomatoes with juice, tomatillo salsa, and chicken broth. Season with oregano and clove. Bring to a simmer over medium-high heat, then reduce heat to medium-low, cover, and simmer 20 minutes.
After 20 minutes, remove 2 cups of the soup (ensure there are no pork cubes in it), and pour into a blender. Hold down the lid of the blender with a folded kitchen towel, and carefully start the blender, using a few quick pulses to get the soup moving before leaving it on to puree. Puree until smooth, then pour back into the cooking pot. This will create a thicker texture for your chili and will eliminate some of the chunky bits of chiles. Continue to simmer, stirring occasionally until the pork is very tender, at least 35 minutes more.