Shredded Spicy Chicken Tostadas (Tinga)

INGREDIENTS

• 1 cup chopped tomatillos (husked and rinsed first)
• 1 clove garlic, minced
• 3 tomatoes (about 1 pound), boiled 30 seconds, peeled and seeded
• 1/2 teaspoon crumbled dried Mexican oregano
• 2 tablespoons pureed chipotle
• 1 tablespoon salt
• 1 tablespoon whole peppercorns
• 1 bay leaf
• 1/2 large white onion, chopped
• 10 store-bought tostadas
• 1 sprig fresh thyme
• 2 cloves garlic
• 1 teaspoon freshly ground black pepper, plus more for seasoning
• 1/4 medium white onion
• 1 1/2 teaspoons kosher salt, plus more for seasoning
• 1 sprig fresh marjoram
• 1 pound boneless skinless chicken breasts
• 4 ounces raw pork chorizo