Preheat oven to 400ºF (204ºC). Line a baking sheet with aluminum foil.
Arrange peppers (15 poblano + 2-4 jalapeños) on the baking sheet, and roast, turning once, for 35-40 minutes or until skins are blackened.
Remove from oven and immediately place peppers in a bowl covered with plastic wrap or place in a plastic bag and seal. Allow peppers to steam for 10-15 minutes. Remove peppers, one at a time, leaving the rest in the bag until ready to peel. Peel pepper and discard skins; set aside peeled peppers.
Slice peeled peppers in half, remove seeds and ribs, and dice the peppers.
Add the cubed pork (3.5-4 pounds) to a mixing bowl and toss with 2 teaspoons salt and 1 teaspoon black pepper.
Heat 2 tablespoons of vegetable oil in a large Dutch oven, or large heavy bottom pot. Brown the pork in batches so as not to crowd the pan, over medium-high heat. Transfer the browned pork to a plate. Repeat with the remaining pork, seasoning the second batch, as above with salt and pepper. Remove and discard all but 2 tablespoons of oil.
If you don't have 2 tablespoons of oil in the pot, make up the difference with more vegetables. Add onion (1 1/2 cups) and sauté over medium-low heat until translucent.
Add garlic (2 tablespoons) and continue to sauté until fragrant, about 1 minute. Sprinkle flour (3 tablespoons) over the sautéd onion and garlic mixture. Continue to cook, over medium heat, whisking constantly, for about 1 minute.
Dissolve the chicken flavor Better Than Bouillon (1 heaping tablespoon) in a 1/2 cup boiling water.
Add dissolved Better Than Bouillon, chicken broth (6 cups), cumin (2 teaspoons), oregano (1 teaspoon), 1 teaspoon salt, browned pork, and chopped chiles. Scrape up all the brown bits from the bottom of the pot as you go. Bring to a boil, then immediately reduce heat and maintain a gentle simmer, with the pot partially covered, until the pork becomes tender, about 60-90 minutes,
Stir in the potato chunks and continue to simmer until they're fork tender, 20-30 minutes. Adjust seasoning.
If you'd like the stew thicker, whisk 2-3 tablespoons of cornstarch with cold water then pour it into the stew. Stir constantly, so the slurry doesn't clump until the stew is thickened. Serve.