Remove the stems and seeds from the dried chiles. Transfer to a glass bowl and cover with water. Cook in the microwave 6 to 7 minutes stirring once during cooking time. Remove from microwave, cover and set aside.
In a large sauce pan, add oil and heat to medium heat. Saute the onions for 3 -5 minutes. Add the garlic, serrano, cumin, paprika, salt, beans with broth and chicken broth. Bring up to a simmer for a few minutes.
Drain the water from reserved chiles, transfer to the blender. Add to warm bean mixture to the blender. Very carefully, put the lid on the blender and hold down with a kitchen towel. Pulse to blend into an smooth bean sauce.
Do not overfill your blender when blending hot foods because the lid may pop off during blending. Blend in batches if needed. Transfer bean sauce pack to sauce pan. Cook on low for 5 minutes. If it's too thick, add a bit more chicken broth.
To Prepare Enfrijoladas: Shallow fry corn tortillas in preheated oil for less than one minute, turning once. Dip fried tortillas in bean sauce and either roll, fold like a taco or fold into quarters and stack onto serving plate. Garnish with crumbled queso fresco and thinly sliced onion for a simple version.