Make the salsa. Combine the olive oil, red wine vinegar, lemon juice, zest, Dijon, garlic, oregano, mint, and parsley in a large mixing bowl. Season to taste with salt and pepper and whisk well. Add in the tomatoes, olives, cucumber, red onion, and roasted red pepper and toss well. Set aside.
Marinate the salmon. Place the salmon filets in a medium baking dish and season with salt and pepper. In a small bowl, whisk together the olive oil, lemon zest, lemon juice, garlic, and oregano with salt and pepper. Pour the marinade over the salmon and turn the salmon pieces over in the mixture so they’re well coated. Marinate for 30 minutes.
Prep the grill. Before using your grill, make sure to clean the grates of any food and debris. Lightly grease the grates with nonstick spray. Preheat your grill to medium heat. If you’re using charcoal, move all the hot coals to one side. Close the lid and wait at least 15 minutes, until the temperature reaches 450 F.
Grill the salmon. Remove the salmon from the marinade and place them on the grill skin-side down and close the lid. Grill for 6-8 minutes, until the skin is crispy and browned. Flip the salmon pieces over and grill for another 2-3 minutes. Remove the salmon from the grill and transfer to a serving platter. You can remove the skin, if desired.
Top the salmon. Add the cubed feta to the greek salsa and toss gently. Top the salmon filets with the salsa and serve with lemon wedges on the side for squeezing.