Preheat your oven to 400°Fand spread sesame seed bun cubes in a single layer on aparchment-lined baking sheet. Drizzle with olive oil and tossto coat. Bake for 10 minutes, or until crispy on the outside.Set aside.Heat a large pot over mediumheat. Add 1 lb. ground beef, 1 teaspoonoregano, 1 teaspoon thyme, and a pinch of koshersalt and fresh cracked pepper. Brown the ground beef,crumbling it as it cooks. Once cooked, remove from the pot and set aside.In the same pot, melt 6 tablespoons butter over mediumheat. Add 1 cupdiced onion, 1 cup sliced carrots, and 1 cupsliced celery. Cook for 10 minutes until thevegetables soften. Add 5cloves minced garlic, 1 teaspoon oregano, and 1teaspoon thyme. Cook for 1 minute untilfragrant.Stir in 4 tablespoons of flour to coat the veggies. Cook for another minute,then add a splash of chicken broth to deglaze the pot. Add theremaining 8 cups chicken broth and the uncookedmacaroni, along with a pinch of salt and pepper. Bring to a simmer,then lower the heat and cook for 5-7 minutes until the pastais al dente. Stir occasionally.Remove the soup from heat,and stir in 1 cup heavy cream and 8 oz. shreddedcheddar cheese until smooth. Add 1 teaspoon white balsamicvinegar, then return the cooked ground beef to thepot. Stir and heat for a couple of minutes until the beef is warmed through.Taste and adjust seasoning with salt and pepper.Serve the soup with thehomemade croutons, and garnish with sliced green onions andadditional shredded cheddar cheese. Enjoy!