Heat your large soup pot over medium heat and add the olive oil. Once shimmering, stir in the finely chopped onion and cook, stirring occasionally, until translucent and fragrant, about 5 minutes.
Add the fresh or thawed peas to the pot, along with the vegetable broth. Bring the mixture to a gentle simmer and cook until the peas are tender and bright green, about 5 minutes. You should hear a gentle bubbling as they cook.
Stir in the chopped mint leaves, allowing their refreshing aroma to fill the kitchen. Let them cook gently for about a minute to infuse the soup with flavor.
Use an immersion blender directly in the pot, or transfer the mixture carefully to a blender, and blend until completely smooth and velvety. Be cautious with hot liquids—blend in batches if necessary. The soup should turn a vibrant, uniform green and feel silky to the touch.
Pour the pureed soup back into the pot if you used a regular blender, then warm gently over low heat. Add lemon juice, season with salt and pepper, and taste to adjust the brightness and seasoning. The soup should be lively, slightly sweet, and herbaceous.
Once heated through and well seasoned, turn off the heat. Ladle the soup into bowls, drizzle with a little extra virgin olive oil, and garnish with a few fresh mint leaves for a beautiful, aromatic finish. Serve immediately while warm and vibrant.
