Heat the oven to 425°F/220°C.
In a large bowl, toss the salmon with the olive oil, lemon juice, parsley, dill, honey, sumac, garlic powder, salt and pepper until evenly coated.
Arrange the salmon in a single layer on a parchment-lined baking sheet. Roast until just cooked through and lightly browned, 10 to 12 minutes. Broil for 1 to 2 minutes for deeper color.
Meanwhile, combine the feta, Greek yogurt, olive oil, herbs, lemon juice and salt in a food processor. Process until smooth and creamy.
Spread the whipped feta over a serving platter and top with the warm salmon. Garnish with fresh herbs and serve immediately.