Melt the butter over medium heat in a large, heavy-bottomed pot. When the butter melts, stir in the onions, carrots, and celery. Cook, stirring occasionally, until they begin to soften, 5 to 6 minutes.

Stir in the garlic, rosemary, red pepper flakes, 1/2 teaspoon of salt, and 1/4 teaspoon of black pepper, and then cook, stirring everything around the pot, for 30 seconds.

Scatter the flour over the vegetables and cook, stirring, until it looks medium blonde in color, about 1 minute.

Slowly whisk in 2 cups of the stock, ensuring no lumps of flour remain.

Pour in the remaining stock and whisk until blended. Increase the heat to a boil, then reduce to a simmer for 20 minutes.

Add the potatoes and bay leaf, then cook, partially covered, until the potatoes are fork-tender, about 20 minutes.

Turn the heat down to low, remove the bay leaf, and stir in the cream and cheese.

Taste for seasoning, then adjust with more salt and pepper as needed.

Serve with fresh herbs on top. For a thick and blended soup, use a potato masher to mash or an immersion blender to blend about half of the potatoes, and then stir back into the soup. (Gallagher, 2026).