Heat the oven to 275 degrees F. Coat the bottom of a baking dish (big enough to fit the fish) with 1½ teaspoons olive oil. Pat the salmon dry, place in the baking dish, coat with 1½ teaspoons olive oil, and sprinkle evenly with salt.
Roast for 20 to 30 minutes or until it’s cooked through, flaky, and reaches 120 degrees F on an instant-read thermometer.
Meanwhile, make the chermoula: In a large well-seasoned cast iron pan, toast the cumin and coriander seeds over medium-high heat until fragrant, about 2 minutes. Transfer to a food processor or mortar and grind just until broken into pieces (you don’t want a fine grind). Reserve the skillet.
Transfer ground spices to a medium bowl, along with ¼ cup olive oil, paprika, and cayenne. Stir to combine.
Return the cast iron skillet to medium-high heat with 2 tablespoons olive oil. Once the oil is shimmering, add the tomatoes, season with salt and pepper, and cook, mostly undisturbed but shaking once or twice, until the tomatoes turn bright red and blister in spots, 6 to 8 minutes.
Add the garlic, stir gently, and cook just until fragrant, another minute. Transfer the tomatoes and garlic to the medium bowl with the spiced oil. Stir to coat and let cool slightly.
Before serving, stir the parsley and mint into the tomato mixture and adjust seasoning to taste. Serve the salmon with the tomato chermoula on top.