In a medium saucepan, heat the coconut oil over medium heat. Add the onions and a pinch of salt. Cook until the onions have softened, about 5 minutes. Add the garlic and stir, cooking for 2 minutes more.
Add the peas and vegetable broth. Cook just until the peas are bright green and no longer frozen, 1 to 2 minutes only.
Quickly but carefully ladle the soup into a blender. Add the dill, lemon zest, and juice. Blend on high until completely smooth. Taste and adjust the seasoning, if necessary.
Transfer the soup to a sauce pan and heat until hot. Serve with a drizzle of olive oil.