When ready to cook, start the Traeger grill on Smoke with the lid open until the fire is established (4 to 5 minutes). Set the temperature to 400 degrees F and preheat, lid closed, for 10 to 15 minutes.
Add dried chilis to a large dutch oven and cook over medium-high heat, stirring frequently, until slightly darkened. Remove chilis and place in a 2-quart microwave-safe bowl. Add half of the chicken stock to the bowl, cover with plastic wrap, and microwave for 5 minutes. Remove from microwave and transfer chilis and liquid to blender. Blend until smooth.
Season chuck steaks generously with salt and pepper. Heat oil in the base of dutch oven over high heat. Add chuck steaks in a single layer, doing in 2 batches if needed. Cook without moving until deeply browned. Flip steaks and brown second side.
Transfer steaks to a cutting board. Cut seared steaks into 1 inch chunks.
Keeping the heat on high, add onions to dutch oven and cook, stirring frequently until translucent. Add garlic, cinnamon, cumin, allspice, and oregano, and cook, stirring until fragrant. Add all meat back into the pan along with chili puree and remaining quart of chicken stock. Stir to combine.
When ready to cook, start the Traeger grill on Smoke with the lid open until the fire is established (4 to 5 minutes). Set the temperature to 250 degrees F and preheat, lid closed, for 10 to 15 minutes.
Place dutch oven in preheated grill with the lid of dutch oven slightly off the side. Braise for 3 hours or until meat is very tender.
Remove from grill, stir in fish sauce, masa and vinegar. Add hot sauce and salt, to taste.
To serve, garnish with cilantro, chopped onions, scallions, grated cheese, avocado, and warm tortillas on side. Enjoy!
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