Prepare the vegetables by peeling and cutting the potatoes into ½-inch cubes, slicing the carrots into ¼-inch rounds, dicing the onion, and mincing the garlic. Set them aside.
Add the ground beef and press it into a flat layer covering most of the surface. Let it cook undisturbed for 4–5 minutes, then flip and break it into large chunks. Continue cooking until browned, though it doesn’t need to be fully cooked through yet.
Add the carrots, celery, and onion to the pot. Cook for about 8 minutes, stirring occasionally, until the onions become soft and translucent. Stir in the minced garlic and cook for another minute.
Mix in the potatoes, diced tomatoes with their juices, beef broth, Worcestershire sauce, thyme, salt, pepper, Maggi Sauce (if using), and bay leaf.
Bring the stew to a gentle simmer, then lower the heat. Cover and let it cook for 20–25 minutes, or until the potatoes are fork-tender.
Whisk the cornstarch with cold water until smooth. Pour this into the stew and stir well. Let it cook for another 2–3 minutes until the broth thickens slightly.
Add the frozen peas and corn, stirring them in. Cook for another 2–3 minutes until heated through.
Taste and adjust seasoning if needed. Serve hot and enjoy!