Pulled Pork Chili Verde

Name: Pulled Pork Chili Verde
Ingredients: 1 head garlic; 0.25 cup olive oil, divided, or as needed; 2.5 pounds fresh tomatillos, husks removed; 4 large green bell peppers, halved and seeded, or more to taste; 4 Anaheim chile peppers, halved and seeded, or more to taste; 3 jalapeno peppers, halved and seeded; 3 sweet banana peppers, halved and seeded; 2 onions, chopped; 3 ribs celery, chopped, or more to taste; 3 pounds shredded, fully cooked pork shoulder; 1 bunch cilantro, chopped; 1 tablespoon dried oregano; 2 teaspoons ground coriander; 2 teaspoons ground cumin; 1 dash ground cinnamon; 1 dash ground nutmeg; 1 pinch salt and ground black pepper to taste; 2 cups chicken stock, divided, or more to taste; 1 (14 ounce) can coconut milk