Peel your potatoes and cut them into bite sized pieces. Put them in a stockpot and cover with water. Bring to a boil and cook for about 4-5 min, then drain - You're only wanting to par-cook these at this stage
Melt your butter in a large stock pot or dutch oven
Add your diced onion and season with salt and pepper. Saute for a couple of minutes, until the onions have softened
Add 1/4 cup flour and stir constantly for another minute or until it gets combined
Pour in your chicken stock and stir until the sauce thickens
Add the par-cooked potatoes along with your rosemary and half and half and let it start to come to a boil
Once the soup is just beginning to boil, cover with a tight fitting lid, turn the heat to low and simmer for 15 minutes
Once the time has elapsed, uncover and give your soup a good stir to make sure nothing has stuck to the bottom. Add your freshly shredded cheese and gently stir until it's fully melted and combined. Taste for seasoning and add additional salt/pepper if needed.Serve this soup with a side of bread for dipping and savor each and every bite. You can thank me later.