While oven is heating cook one package of bacon until very crispy.
Combine the potatoes, onion, garlic and leeks on a sheet pan in a single layer. Add the olive oil, salt, and pepper and toss to coat the vegetables evenly. Roast for 40 to 45 minutes, turning half way through the cooking, until very tender.
Remove the pan from the oven and move the roasted vegetables into a soup pot. Stir in the heavy cream and vegetable stock and add 3/4 of the cooked bacon cook over low heat, scraping up any crispy roasted bits sticking to the pan.
Use an immersion blender or in batches, transfer the roasted vegetables to a food processor fitted with the steel blade, aand make a puree. Pour the puree into a large pot or Dutch oven and taste test to check the seasonings.
When ready to serve add the extra crispy chopped bacon and shredded cheese.