In a large pot, heat the vegetable oil over medium-high heat. Add the beef stew meat and brown on all sides, about 5-7 minutes. Remove the beef and set aside.
In the same pot, add the chopped onion and garlic. Sauté for 2-3 minutes until the onion is translucent.
Return the browned beef to the pot. Add the carrots, celery, green beans, corn, diced tomatoes, beef broth, thyme, basil, salt, pepper, potatoes, and bay leaf. Stir to combine.
Bring the mixture to a boil, then reduce the heat to low. Cover and simmer for 1.5 to 2 hours, or until the beef is tender and the vegetables are cooked through. Stir occasionally.
Remove the bay leaf before serving. Taste and adjust seasoning if necessary.