Preheat the oven to 350°F and set an oven rack in the middle position. Line 1 baking sheet with parchment paper or heavy-duty aluminum foil for easy clean-up if desired.
Heat the olive oil in a medium skillet over medium heat. Add the onion and poblano pepper and cook, occasionally stirring, until softened, 10 to 15 minutes. Add the garlic and cook 1 minute more. Add the tomato paste and cook for 1 minute, stirring to incorporate. Add the Worcestershire sauce, chicken flavored bouillon, pepper, dijon mustard, and thyme, and mix well. Allow to cool to room temperature.
Meanwhile, whisk to combine the ketchup, brown sugar, cider vinegar, and Dijon mustard in a small bowl. Set aside.
Whisk the eggs and ¼ cup of ketchup mixture in a large bowl until well combined. Add the onion and pepper mixture and the chopped cilantro or parsley and whisk to combine. Add the breadcrumbs and the ground turkey. Using your hands, mix until well combined.
Divide the meatloaf mixture into two equal mounds. Transfer to the prepared baking sheet and shape each mound into a Shape into a 9-by-5-inch oval loaf with your hands. Spread the remaining kepchup mixture over the loaves. Bake for about 45 minutes or until the internal temperature is 165 degrees F. and the meatloaf is cooked through.
To prevent the top of the meatloaf from cracking, place a pan of hot water on the rack underneath your meatloaf, so the oven is filled with gentler, moist heat. Scrape any fat away from the sides of the loaves, then transfer the loaves to a platter. Slice and garnish with cilantro or parsley if desired.