Step 1

Put chicken thighs in a saucepan and cover with 3 cups water. Add scallions, bay leaf, thyme, peppercorns, allspice, cloves and 1/2 teaspoon kosher salt. Simmer for 30 minutes, then remove chicken and cool. Shred chicken with your fingers, discarding chicken skin and bone. Strain broth and reserve. You should have about 2 cups shredded chicken.

Step 2

Put olive oil in a skillet over medium heat. Add diced yellow onion, season with salt and cook until softened and a bit browned, about 5 minutes. Add garlic and cumin and cook for 1 minute more. Add chopped chipotle chile and adobo sauce and stir to combine. Add shredded chicken, salt lightly and stir to coat. Add chicken broth and simmer for 2 or 3 minutes, until sauce has thickened somewhat. Keep warm.

Step 3

Heat the tortillas over steam or by your favorite method, keeping them soft and pliable.

Step 4

Build the tacos quickly: Put a spoonful of the saucy chicken in the center of each tortilla. Top with a teaspoon of chopped white onion, a few slivers of serrano chile, some radish and avocado slices, a teaspoon of queso fresco and a teaspoon of crème fraîche. Add a few cilantro springs and a small pinch of oregano. Serve immediately with lime wedges on the side.