Heat in a large skillet over medium-high heat. Melt the butter and add garlic and fry until fragrant (about 1 minute). Add shrimp and fry two minutes each side, until just cooked through and pink. Transfer to a bowl and set aside.
Fry the onion in the butter remaining in the skillet. Pour in the white wine (if using), and allow to reduce slightly.
Add the sun dried tomatoes and fry for 1-2 minutes to release their flavors.
Reduce heat to low-medium heat, add the half and half and bring to a gentle simmer, while stirring constantly.
Season to taste with salt and pepper.
Add in the spinach leaves and allow to wilt in the sauce, add in the parmesan cheese. Allow sauce to simmer for a further minute until the cheese melts through the sauce. (for a thicker sauce, add the milk/cornstarch mixture to the center of the pan, and continue to simmer while quickly stirring the mixture through until the sauce thickens.)
Add the shrimp back into the pan; sprinkle with the basil, oregano, rosemary and parsley, and stir through.
Serve over pasta, kluski noodles, rice or steamed vegetables.