Preheat oven to 400 F.
Add salmon to baking dish, then press cashews onto fillets and sprinkle with garlic powder.
Bake for 15-20 minutes (until fillets are cooked through).
Allow salmon to cool, then chop into chunks.
Combine crema ingredients.
Top tostada shells with broccoli slaw, salmon, remaining toppings, and crema.