In a heavy bottomed pan, heat some oil. Add a chopped onion, stir till slightly brown. Add a tbsp freshly grated garlic. Stir well, add chopped cauliflower and chopped zucchini (here I used just the outer sliced skin portion saved from another recipe). Mix everything well, add salt and pepper and let cook for about 5 minutes. Add a can of coconut milk, stir and simmer till all vegetables are cooked through (about 15 minutes). Let cool, then blend with an immersion blender till smooth. Add lemon juice, and serve garnished with chopped green onions.