Preheat an oven to 450 F. Line a baking sheet with parchment paper and set aside.
Make the raita. Using a box or cheese grater, grate the cucumber into a small mixing bowl. Stir in the yogurt, cumin, garlic, lemon juice, mint, and cilantro and season to taste with salt and pepper. Refrigerate until ready to serve.
Prep the salmon. Make sure the skin is removed from the salmon and cut it into 2 inch cubes. You could also keep the salmon in filets.
Marinate the salmon. In a large mixing bowl, whisk together the yogurt, ginger, garlic, lemon zest, chili powder, cumin, coriander, garam masala, turmeric, sugar, salt, and pepper. Toss with the cubed salmon and marinate for 15-20 minutes.
Bake the salmon. Lay the salmon cubes on the prepared baking sheet with a bit of room between each piece. Transfer the baking sheet to the oven and cook for 8 minutes. Broil for 1-2 minutes, until the salmon is browned.
Serve. Serve the salmon over basmati rice with the raita. Top with thinly sliced red onion, fresh mint, and cilantro. Serve with naan on the side and lemon wedges for squeezing.