Adjust rack to top position (top and middle positions for 4 servings) and preheat oven to 425 degrees. Wash and dry produce.

Cut potatoes into ½-inch-thick wedges.

Pat salmon* dry with paper towels; season all over with salt and pepper. 

Toss potatoes on one side of a baking sheet with a drizzle of oil, garlic powder, salt, and pepper (for 4, spread out across entire sheet). Place salmon, skin sides down, on empty side of sheet (for 4, place salmon on a second baking sheet; roast potatoes on top rack and salmon on middle rack). Roast on top rack until salmon is cooked through and potatoes are beginning to soften, 10-12 minutes.

Once salmon is cooked through, remove sheet from oven and carefully transfer salmon to a large bowl. Return potatoes to top rack and roast until browned and tender, 10-15 minutes more. 

While salmon and potatoes roast, roughly chop artichoke hearts. Zest and quarter lemon. 

Remove and discard skin from salmon. Using two forks, finely flake salmon in bowl.

Add panko, half the Old Bay Seasoning, two packets of mayonnaise, and a large drizzle of olive oil (all the Old Bay Seasoning and four packets of mayonnaise for 4 servings). Stir until combined and mixture begins to stick together. Set aside to cool.

In a medium bowl, combine artichoke hearts, half the lemon zest, a drizzle of olive oil, and juice from one lemon wedge (two wedges for 4 servings).

In a small bowl, combine sour cream, remaining mayonnaise, remaining lemon zest, a drizzle of olive oil, juice from one lemon wedge (two wedges for 4 servings), and a pinch of salt and pepper.

Once salmon mixture is cool enough to handle, form into four ½-inch-thick patties (eight patties for 4 servings).

Heat a large drizzle of oil in a large, preferrably nonstick, pan over medium-high heat. Add salmon cakes and cook until warmed through and golden brown, 3-4 minutes per side (for 4, you may need to cook in batches). (Flip the salmon cakes carefully—they're fragile! Even if they break, they'll still be delicious!)

In a second medium bowl, toss arugula with a drizzle of olive oil and a squeeze of lemon juice.

Divide salad and potatoes between plates in separate sections. Arrrange salmon cakes over salad and drizzle with as much aioli as you like. Top salmon cakes with artichokes. Serve with any remaining lemon wedges and any remaining aioli on the side for dipping.