In a large pot over medium - high heat, add pancetta and cook until browned and crispy, stirring frequently, about 10 minutes. Remove from pan.
Add garlic and cook in the pancetta fat for about 2 - 3 minutes, or until fragrant. If you are making this vegetarian, use a 1/2 Tbsp of olive oil or butter instead of pancetta fat.
Add butter, leeks, and rosemary and stir to combine and melt butter. Cook 5 -7 minutes stirring frequently, until leeks are starting to get soft.
Add vegetable stock, and water and stir. Bring to a simmer and add heavy cream. Simmer for 10 minutes.
Add spinach and cook 5 additional minutes, until wilted. Using an immersion blender (or a regular blender) and blend until smooth.
Add pancetta back to pan, white beans, and orzo. Cook for another 10 minutes. Serve with parmesan and Italian bread.