1. Heat a large (12-inch) cast-iron skillet over medium heat. About 4 minutes, add chiles; cook, turning occasionally, until fragrant. Should be lightly toasted. Transfer to a blender; add the 1 1/2 cups boiling water. Mixture should stand for about 30 minutes. Add tomato sauce, cilantro, and salt and process until smooth for about 20 seconds. Set aside.

1. Heat oil in a large cast-iron skillet over medium-high heat. Add chorizo. Cook, stirring occasionally, until crumbled and browned for about 6 minutes. Stir in fideo, garlic, bay leaf, and chile de árbol. Cook, stirring occasionally. Fideo should be lightly toasted and turning opaque, 4 to 5 minutes.

2. Stir in chile base. Reduce heat to low. Cover and cook until fideo is tender. Liquid should be fully absorbed within 15 to 20 minutes, stirring once after 8 minutes. Remove and discard bay leaf and chile de árbol. Transfer mixture to a medium bowl, and stir in cilantro. Let cool 20 minutes. Stir in Monterey Jack cheese.

3. Top each tortilla with 1/3 cup fideo filling; fold each tortilla in half, pressing gently. Heat a large cast-iron skillet or grill pan over medium-high heat. Toast tacos until tortilla is lightly charred and filling is warmed through, 2 to 3 minutes per side. Be sure to work in batches. Top tacos with Mexican crema, avocado slices, and crumbled queso fresco. Garnish with cilantro.

4. Serve immediately.