Preheat your oven to 375°F (190°C). Poach the firm white fish in a skillet over medium heat for about 8–10 minutes until it flakes easily. Shred the fish and season.

In a blender, combine chipotle peppers and sour cream (or Greek yogurt). Blend until smooth. Taste and adjust seasoning, then set aside.

Warm the corn tortillas in a dry skillet for about 15-20 seconds on each side to make them pliable.

Spoon the shredded fish filling into each tortilla, roll them up tightly, and place seam-side down in a greased baking dish. Pour chipotle cream sauce over the enchiladas.

Bake the enchiladas in the preheated oven for 20-25 minutes until bubbly and edges are slightly crispy.

Allow to cool for a few minutes, then serve topped with sliced avocado and pickled red onions.