Rub salmon with avocado oil (about 1/2 tsp per filet) season generously with salt and pepper.
Heat 1 tbsp avocado oil in a large skillet. Add salmon skin side down and sear until crispy (about 2 minutes), flip and cook for an additional 2 minutes. Remove from pan and set aside.
Add additional avocado oil to pan and saute garlic, shallot, ginger, and serrano chili for 3 minutes or until tender. Add curry paste and stir to coat all vegetables in curry paste. Add coconut milk and fish sauce and scrape to release any browned bits from the bottom of the pan.
Add broccoli florets, bring to a simmer, cover for 4 minutes or until broccoli is tender.
Add salmon back to the ban, spoon sauce over the salmon and simmer until salmon is warmed through.
Top with cilantro, lime juice, and sliced raw serrano (optional).