Dice onion. Add olive oil to saute pan and heat on medium. Add onion and salt. Saute for 3 minutes.
Mince garlic and add to onion. Continue cooking on medium for 2 minutes.
Add diced tomatoes, lemon zest, lemon juice, & shrimp stock. Cook on medium for 5 minutes
Add zucchini noodles and peeled shrimp. Stir to combine all ingredients. Cook on medium for 3 minutes. Stir continuously ( I use tongs) and flip shrimp often to get an even cook.
Add butter and stir. Turn heat off, cover and let sit for 3-5 minutes. This will allow the shrimp to finish cooking without overcooking.
Plate, Garnish with both grated and shaved Parmesan cheese. Serve & Enjoy!
Notes
If you are cooking on an electric stove, remove pan from burner when you cover the shrimp.