How to Make It
Heat a large (12-inch) cast-iron skillet over medium. Add chiles; cook, turning occasionally, until fragrant and lightly toasted, about 4 minutes. Transfer chiles to a blender; add 1 1/2 cups boiling water. Let stand 30 minutes. Add tomato sauce, cilantro, and salt. Process until smooth, about 20 seconds. Set aside.
Heat oil in a large cast-iron skillet over medium-high. Add chorizo, and cook, stirring occasionally, until crumbled and browned, about 6 minutes. Stir in fideo, garlic, bay leaf, and chile de árbol. Cook, stirring occasionally, until fideo is lightly toasted and turning opaque, 4 to 5 minutes. Stir in chile base. Reduce heat to low, cover, and cook until fideo is tender and liquid is fully absorbed, 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.
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. Working in batches, toast tacos until tortilla is lightly charred and filling is warmed through, 2 to 3 minutes per side. Top tacos with Mexican crema, avocado slices, and crumbled queso fresco. Garnish with cilantro. Serve immediately.
Use fresh tortillas; they’re less likely to tear or crack when charring.