In a bowl combine the clean shrimp. Mix in the chile ancho salsa and stir to coat evenly. Set aside.
In a large skillet, add 3-4 tbs of oil and heat to medium. Add the fideo. Fry and toaste the fideo, stirring as needed until golden brown. Remove from heat and set aside.
In a large pot, at medium heat, add 2 tbs of oil. Add the onion, garlic, jalapeño and bell pepper. Season lightly with salt and pepper. Saute for 5 minutes.
In the blender, combine the roma tomatoes, tomato sauce, oregano and a pinch of salt. Blend on high until smooth.
Pour blended tomato sauce into the pot with aromatics. Stir well to combine and cook for 7-10 minutes. Add the warm chicken broth and bring up to a simmer.
Taste for salt, add cilantro and the previously toasted fideo. Cook at a steady simmer for 7-8 minutes or until fideo is cooked through. Add the reserved shrimp in and stir gently. Cook for another 5 minutes. Remove pot from heat and let sit for a few minutes before serving. Ladle into bowls and garnish with cilantro, lime, onion, avocado and diced chile serrano or salsa macha. Yields up to 6 servings.