Pat the salmon dry and sprinkle both sides lightly with salt and pepper.
Heat a medium nonstick or cast-iron skillet over medium-high heat. Add 1 tablespoon of the sun-dried tomato oil.
Place the salmon skin-side down in the skillet. Cook until the skin is browned and crispy and the salmon is mostly cooked through, about 5 to 7 minutes. If the skin starts to brown too fast, lower the heat. Transfer the salmon to a plate, skin-side up. It will finish cooking later.
Lower the heat to medium. Add the chopped onion to the skillet and season lightly with salt. Cook, stirring occasionally, until very soft, about 5 to 7 minutes.
Reduce the heat to medium-low. Add the remaining tablespoon of sun-dried tomato oil, the oregano, and crushed red pepper. Stir for a few seconds to wake up the flavors. Add the tomato paste and cook, stirring often, until it darkens slightly, about 3 minutes.
Pour in the clam juice and raise the heat to medium-high. Let it simmer until reduced by about half, 4 to 5 minutes. Lower the heat again, add the cream and sun-dried tomatoes, and stir constantly until the sauce thickens slightly, about 5 minutes. Taste and adjust seasoning if needed.
Place the salmon back into the skillet flesh-side down, keeping the crispy skin out of the sauce. Lower the heat and let it gently simmer until cooked through, about 1 minute. The salmon will continue to cook as it rests. Top with fresh basil if using and serve warm.
