In a soup pot over medium heat, heat 1/4 cup vegetable broth and saute the sweet onion for 3-4 minutes, until starting to soften.
Add the garlic and saute another 1-2 minutes.
Add the remaining 2 1/2 cups vegetable broth, broccoli, celery, peas, and green onions. Turn down the heat to medium-low and simmer 10-15 minutes until vegetables are tender.
Transfer the soup to a blender and add the leafy greens, beans, lemon juice, dill, mint and salt. Use the tamper to pack the greens down. Blend until smooth. You may need to work in batches if your blender is on the smaller side.
Pour the soup back into the soup pot, taste and adjust seasonings as necessary. Add the coconut milk, if desired, and stir to combine.