Combine seasoning mix in a mixing bowl and set aside.
Season meat with salt and pepper. Heat 1 Tbsp vegetable oil in a large dutch oven or heavy bottomed pot and heat over MED HIGH heat. Once hot, add 1/3 of the beef and sear for 2 minutes, without stirring. Flip beef pieces over and cook another 1-2 minutes. Remove to a plate.
Repeat with another 1/3 of the beef, and then one last time with the remaining 1/3 of the beef, adding more oil if necessary, putting all the beef on the same plate after searing.
Add butter and reduce heat to MED. Add in onion, poblano peppers, and jalapeno pepper. Cook, scraping the bottom of the pot with a wooden spoon to loosen any browned bits from the beef, for 5 minutes.
Add garlic and cook 1 minute. Add in tomato paste and seasoning mix (from step 1) and cook another 1 minute, stirring often.
Stir in brown sugar, tomato sauce, chipotle pepper, beef broth and water. Carefully return beef back to the pot.
Add bay leaves and let come to a low boil. Once boiling, reduce heat to LOW and simmer, uncovered, for 3 - 3 1/2 hours. Stir every hour, at least.
If chili becomes too thick during the simmering, add a splash of extra broth or water.
Remove bay leaves, and serve hot, garnished as desired.