What is that in my tomato soup soup

Recipe from The Amateur Gourmet with modifications

Spicy Tomato and Blue Cheese Soup
from "Michael Symon's Live To Cook" by Michael Symon

Serves 4 to 6

Ingredients:
2 tablespoons olive oil
1 medium red onion, finely chopped
Kosher or sea salt
4 garlic cloves, sliced or chopped
1 28-oz can San Marzano or Roma tomatoes, with their juice
1 1/2 cups Chicken Stock
3/4 cups heavy cream or yogurt or low fat cream
2 tablespoons sriracha or tabasco or other hot sauce
1 tablespoon fresh or dried oregano leaves
1/2 cup Roth Kase Buttermilk or any other kind of Blue cheese

Heat the olive oil in a 4-quart pot over medium heat. When the oil is hot, add the onion and a three-fingered pinch of salt and sweat for 2 minutes. Add the garlic and continue to sweat for 2 more minutes. Add the tomatoes, their juice and the stock and bring to a simmer. (I added a little more salt here too). Add the cream, sriracha sauce, and oregano and simmer for 45 minutes.

Pour the soup into a blender, add the blue cheese, and blend until smooth, working in batches if needed.

Strain through a fine-mesh strainer into a clean pot, taste, adjust the seasoning if necessary, and reheat to serve. The soup will keep, covered in the refrigerator, for a few days.