Preheat the olive oil and butter in a pot large enough to fit everything over medium low to medium heat.
Add the onions and cook until translucent and slightly browned, stirring occasionally. This should take about 15 minutes.
Add the carrots and cook, stirring often. The goal is to soften them, so don’t rush this step.
Add salt, ginger, and lemon peel. Cook for a few more minutes, until you can sense the aroma of lemon and ginger.
When the carrots are soft and pierced easily with a fork or a knife, add chicken stock and bring to boil. Let cook, partially, for 3-5 minutes.
Remove from heat and let cool for a few minutes.
While the soup is cooling , place prosciutto strips onto an oven safe dish under the broiler on low setting for a couple of minutes. It will crisp and if you like - you can “crinkle” them slightly to make them look curled up.
Using an immersion blender, process soup until smooth.
Stir in the heavy cream, salt, and pepper.
Taste and correct the seasoning, if needed. Serve topped with crispy prosciutto and more black pepper.