Turn your Instant Pot to the "Sauté" setting. Add 1 teaspoon of coconut oil and let it heat up. Once hot, add the 3 minced garlic cloves and sauté for about 30 seconds until fragrant.
Add the 1 pound of dried spaghetti to the pot, followed by 4 ¼ cups of water. Stir to ensure the pasta is submerged. Close the lid and set the Instant Pot to "Manual" or "Pressure Cook" for 4 minutes. Perform a quick release of the pressure once done.
Open the lid and add the 1 pound of raw jumbo shrimp to the pot. Stir well to combine with the pasta. Close the lid again and set the Instant Pot to "Manual" or "Pressure Cook" for 2 more minutes. Perform another quick release.
In a separate bowl, whisk together the ¾ cup light mayonnaise, ¾ cup Thai sweet chili sauce, ¼ cup lime juice, and 1 tablespoon Sriracha sauce. Pour the sauce into the pot and gently toss everything together.
Add salt and pepper to taste, then sprinkle the ½ cup chopped scallions over the top. Stir gently and serve immediately.
