Preheat the Oven:

Preheat your oven to 350°F (175°C).

Prepare and Coat the Beef:

Combine flour, onion powder, garlic powder, and black pepper in a large resealable bag. Add the beef stew meat and shake to coat evenly.

Brown the Beef:

Heat 1 tablespoon of vegetable oil in a Dutch oven over medium heat. Using tongs, remove the coated beef from the bag and add it to the pan, reserving any leftover flour mixture. Brown the beef on all sides, then transfer it to a plate.

Cook the Onions:

Add the remaining tablespoon of vegetable oil to the Dutch oven and sauté the chopped onions over medium heat for 3-4 minutes, until softened and slightly golden.

Build the Gravy:

Sprinkle the remaining flour (about 1½ tablespoons) into the Dutch oven and cook for 2 minutes, stirring constantly. Add the oregano, basil, and marjoram, and cook for 30 seconds, stirring frequently. Gradually stir in the beef broth and cook for 2 minutes, stirring occasionally, until the mixture begins to thicken.

Bake the Stew:

Return the browned beef to the Dutch oven. Cover the pot and bake in the preheated oven for 1 hour.

Add Vegetables and Potatoes:

After 1 hour, add the cubed potatoes and the frozen mixed vegetables (corn, carrots, peas, and green beans) to the pot. Cover and return to the oven for an additional 30 minutes, or until the stew and vegetables are tender.

Serve:

Remove from the oven, stir gently, and serve warm. Enjoy with your favorite bread or a side salad!