Add the chicken thighs, 2 cloves of garlic, 1/2 of the onion, bay leaf, peppercorns, and salt to a pan, then add water to cover (about 4 cups). Place the pan over medium heat. Cover it, and cook for 20 minutes, or until the chicken is at an internal temperature of 160°F and fork tender.
Remove the chicken thighs from the broth. Reserve the broth. Shred the chicken with two forks.
Add oil to a saucepan on medium heat. Dice the remaining ½ onion and add it to the pan. Mince the remaining 2 cloves of garlic and add to the pan. Cook for about 2 minutes, until the onions steam and the garlic is fragrant.
Once the onions and garlic are fragrant, chop the chipotles in their sauce and add them to the pan. Stir well to incorporate. Then add the pulled chicken and 1/4 cup of the reserved broth. Combine thoroughly and taste. For more heat, mix in more adobo sauce. For saucy pulled chicken, add a touch more of the broth and stir. Once the sauce has thickened to a velvety consistency, take the chicken off the heat.
To make the pineapple salsa, finely chop the pineapple, onion, jalapeño, and cilantro. Combine the chopped pineapple, onion, juice of one lime, cilantro, and salt to taste.
Assemble the tacos. Add 1/4 cup of pulled chicken to a corn tortilla and top with pineapple salsa. Serve these babies up and enjoy a weeknight win!