Stage 1: Preparation (10 Minutes)

1. Preheat and Prepare: Begin by preheating your oven to 400°F (200°C). Line a large baking sheet with parchment paper or aluminum foil. This is a crucial step for easy cleanup and prevents the salmon from sticking.
2. Prepare the Salmon: Take your salmon fillets and pat them completely dry on all sides with a paper towel. This is one of the most important yet overlooked steps. Removing excess moisture allows the salmon to roast rather than steam, and it helps the spice rub adhere properly to the flesh, creating a more flavorful crust.
3. Create the Spice Rub: In a small bowl, combine the smoked paprika, garlic powder, onion powder, ¾ teaspoon of kosher salt, and ½ teaspoon of black pepper. Whisk them together with a fork to ensure they are evenly distributed.
4. Season the Salmon: Place the dried salmon fillets on your prepared baking sheet, leaving some space between each one. Drizzle the 2 tablespoons of olive oil evenly over the tops of the fillets. Use your fingers or a pastry brush to coat the entire top surface of each fillet. Sprinkle the spice rub mixture evenly over the oiled fillets. Gently pat the spices into the flesh to help them stick.

Stage 2: Making the Avocado Mash (While Salmon Bakes)

1. Prepare the Avocados: While the salmon is getting its initial seasoning, you can prepare the mash. Slice your ripe avocados in half lengthwise and remove the pits. Scoop the green flesh into a medium-sized mixing bowl.
2. Mash to Your Liking: Using a fork or a potato masher, mash the avocado to your desired consistency. For a chunkier, more rustic texture, mash lightly, leaving some larger pieces. For a creamier, smoother mash, continue mashing until it reaches a buttery consistency.
3. Add the Flavor: Add the fresh lime juice, finely chopped cilantro, minced red onion, minced garlic, and ½ teaspoon of kosher salt to the bowl with the mashed avocado. If you enjoy a touch of spice, add the optional red pepper flakes now.
4. Mix and Taste: Gently stir all the ingredients together until they are just combined. Over-mixing can make the mash gummy. Give it a taste and adjust the seasoning if necessary. It might need another pinch of salt or a small squeeze of lime juice to make the flavors pop. Set the mash aside. The lime juice will keep it vibrant green while the salmon cooks.

Stage 3: Baking and Assembling (12-15 Minutes)

1. Bake the Salmon: Place the baking sheet with the seasoned salmon into your preheated 400°F (200°C) oven. Bake for 12-15 minutes. The exact time will depend on the thickness of your fillets.
2. Check for Doneness: Salmon is perfectly cooked when it is opaque all the way through and flakes easily when gently pressed with a fork. The most accurate way to check is with an instant-read thermometer inserted into the thickest part of the fillet; you are looking for a temperature between 130-140°F (54-60°C) for a moist, tender result. The FDA recommends 145°F, but remember the fish will continue to cook for a minute or two after being removed from the oven (this is called carryover cooking).
3. Assemble and Serve: Once the salmon is cooked to perfection, remove the baking sheet from the oven. To serve, spoon a generous amount of the fresh avocado mash onto each plate, creating a bed for the fish. Carefully place a warm baked salmon fillet directly on top of the mash. Serve immediately and enjoy the incredible contrast of warm, flaky fish and cool, creamy avocado.