In a large skillet, heat the olive oil over medium heat. Add the diced onion and sauté until translucent, about 5 minutes.
Stir in the minced garlic and grated ginger, cooking for an additional minute until fragrant.
Add the red curry paste to the skillet and stir well to combine with the onion mixture. Cook for another 2 minutes.
Pour in the coconut milk, soy sauce, and lime juice. Stir to combine and bring the mixture to a gentle simmer.
Add the salmon chunks to the skillet, gently stirring to coat them in the sauce. Cook for about 5-7 minutes, or until the salmon is cooked through and flakes easily with a fork.
Stir in the cherry tomatoes and spinach leaves, cooking for an additional 2-3 minutes until the spinach is wilted and the tomatoes are warmed through.
Season with salt and pepper to taste.
Serve the coconut curry salmon hot, garnished with fresh cilantro and lime wedges on the side.