Season with salt to taste and set aside. Make avocado crema: Slice remaining scallions and add to blender with mayonnaise, sour cream, peeled avocado, remaining cilantro, jalapeño and garlic.
Bake at 375F for 20 minutes. 3) Make Avocado Crema: Blend avocado, sour cream, lime juice, and cilantro until smooth. Drizzle over enchiladas.