In a large bowl, add the ground beef, breadcrumbs, milk, egg, salt, pepper, garlic powder and onion powder. Mix everything together until just combined. Form the mixture into evenly sized meatballs.
Heat a little olive oil in a large skillet, Dutch oven or deep sauté pan over medium-high heat. Add the meatballs and brown them on all sides. They do not need to be completely cooked through at this point because they’ll finish cooking in the stew. Remove them from the pan and set them aside.
Add the onion, carrot, celery and potatoes to the same pan, adding another drizzle of olive oil if needed. Season the vegetables with salt, pepper and Italian seasoning. Sauté for about 10 minutes, stirring occasionally, until the potatoes begin to brown. Add the garlic and cook for another minute.
Add the crushed tomatoes and vegetable broth. Season with additional salt, pepper, garlic powder and Italian seasoning. Stir in the frozen peas and bring everything to a gentle simmer.
Cover and simmer for about 25 minutes, or until the meatballs are completely cooked through and the potatoes and vegetables are tender. Give the stew a final stir, adjust the seasonings if needed and serve warm.