Heat the vegetable oil in a large heavy-bottomed pot or Dutch oven over medium-high heat.
Add the beef cubes in batches, making sure not to overcrowd the pot, and brown them on all sides, about 5 minutes per batch. Remove browned beef and set aside.
In the same pot, add the diced onion and cook until softened, about 5 minutes.
Add the minced garlic and cook for 1 minute until fragrant.
Return the browned beef to the pot and stir in the tomato paste. Cook for 2 minutes, stirring frequently.
Pour in the beef broth and water, scraping the bottom of the pot to release any browned bits.
Add the dried thyme, dried rosemary, bay leaves, salt, and black pepper. Stir to combine.
Bring the stew to a boil, then reduce heat to low, cover, and simmer for 1 hour 45 minutes, or until the beef is tender.
Add the carrots, celery, and potatoes to the pot. Cover and continue to simmer for 30 minutes, or until the vegetables are tender.
Stir in the frozen peas and frozen green beans and cook for an additional 5 minutes.
In a small bowl, whisk together the all-purpose flour and cold water until smooth to create a slurry.
Gradually stir the slurry into the stew and cook for 5 minutes, stirring frequently, until the stew thickens.
Remove bay leaves and adjust seasoning with additional salt and pepper if needed.
Allow the stew to cool completely before portioning into freezer-safe containers or bags.
Label the containers with the date and freeze for up to 3 months.
To reheat, thaw the stew overnight in the refrigerator and warm on the stove over medium heat until heated through.