Heat olive oil in a large saucepan over medium-high. Add onion and cook until soft, about 2 minutes
Stir in garlic, green onion, bell pepper, celery, carrot, potato, and fresh herbs; cook for another minute, stirring constantly.
Add vegan bouillon, vegetable broth, Italian seasoning, onion powder, garlic powder, and bring to a boil.
Reduce heat to simmer until vegetables are tender, about 15 minutes or until the potatoes are tender
Add cayenne pepper and salt to taste.
To thicken, mash some of the potato cubes or mix 1 tablespoon of cornstarch in 2 tablespoons of cold water and add to the stew, constantly stirring until it thickens.