In a large pot over medium-high heat, melt the butter and olive oil together.
Add the onions and garlic and cook until the onions are softened and translucent, about 5 minutes.
Add the potatoes and chicken broth and bring to a boil.
Reduce the heat to low and simmer, covered, for 25 minutes, or until the potatoes are tender.
Using a slotted spoon, remove the potatoes from the pot and set aside.
In a small bowl, whisk together the flour, thyme, oregano, parsley, garlic powder, onion powder, salt, and pepper.
Whisk in 1 cup of the broth from the pot until the mixture is smooth.
Add the flour mixture to the pot and stir until the mixture thickens, about 5 minutes.
Return the potatoes to the pot and stir in the heavy cream.
Simmer for 10 minutes, stirring occasionally.
Garnish with freshly chopped parsley and serve.