Bring 2 cups water to a boil in a medium pot. Reduce to simmer and add the frozen peas. Cook until tender, 3 to 4 minutes.
Transfer the peas and cooking water to a blender and puree until smooth, 2 minutes.
With the machine running, slowly drizzle in the olive oil to emulsify.
Mix in the salt; taste and season with more salt if desired.
Transfer the soup to bowls. Garnish with microgreens if using.