Season shrimp with salt/pepper/garlic salt and set aside.
Bring a large stock pot to a boil. Salt generously. Add pasta and cook for 6-8 minutes. Drain and rinse with warm water. Set aside.
Heat a large non-stick skillet to med-high heat with 1 tbsp of oil. Add shrimp in a single layer and sear for 2-3 minutes on each side until shrimp turn a light pink and curl slightly. Remove from pan.
To hot pan add remaining olive oil. Once oil is hot, add onions. Saute until tender.
Add white wine and lemon juice, scraping the bottom of pan with back of spoon.
Add pesto and stir until smooth.
Replace shrimp and pasta to pan and heat through.
Remove from heat and add tomatoes and fresh spinach tossing lightly until everything is coated with the sauce.