Pat the salmon fillets dry and season both sides with salt and pepper.
Heat the olive oil in a large skillet over medium heat until shimmering.
Place the salmon in the skillet skin-side down and cook about 7 minutes, then flip and cook an additional 3 minutes, until the salmon is just barely pink in the center; transfer to a plate and set aside.
Reduce heat to medium-low, add the minced garlic to the same pan and cook 1 minute until fragrant.
Add the heavy cream, chicken broth, garlic powder, and Italian seasoning to the pan and bring to a gentle simmer.
Whisk the cornstarch into the sauce until smooth, then simmer 1–2 minutes to thicken slightly.
Stir in the Parmesan cheese until melted, then add the chopped spinach and sun-dried tomatoes and simmer until the spinach wilts.
Return the seared salmon to the skillet and spoon sauce over the fillets; heat for 1–2 minutes to warm through, then serve.
