Heat the olive oil in a large pot on medium-high heat. Add the onion and sauté until it's lightly browned (5-7 minutes).
Add the garlic and cook until fragrant (about 30 seconds).
Add the celery, carrots, little potatoes, veg broth, water, and Italian seasoning. Increase the heat to high and bring to a gentle boil. Reduce heat to medium-low and cover the pot with the lid slightly ajar. Let the soup simmer for 10 minutes.
Add the turkey meat and allow the soup to simmer for another 10 minutes or so.
Stir in the cream and season with salt & pepper to taste.
You don't need to use little potatoes... regular ones are fine as long as the weight is similar. I just find them easy.
I used 2 cups cooked turkey, but you could definitely add a lot more if you need to!