Melt the butter using the sauté feature on the Instant Pot. Add the onion, garlic and tomato paste. Sauté for 2-3 minutes, or until the garlic is fragrant. Stir frequently to prevent burning. Add the white wine and deglaze the bottom of the insert. Let simmer for 2 minutes.
After 2 minutes, add the salt, cream, red pepper flakes and mascarpone. Stir until the cheese is melted and combined with the cream.
Add the water and linguine. Stir well. Secure the lid onto the Instant Pot. Cook over high pressure for 4 minutes. Turn off the Instant Pot and do a quick pressure release after 6 to 8 minutes.
Remove the lid and add the shrimp. Stir well to combine. Using the sauté feature, cook the shrimp for 5-6 minutes. Stirring frequently to prevent burning.
Once the shrimp and pasta is cooked add the parmesan, arugula and basil. Stir well to combine. Salt to taste and serve warm.