Preheat oven to 400°F/200°C.
Combine flour, salt, pepper, paprika & garlic powder in a zip lock baggie. Add meat and shake to coat.
In heavy oven-proof casserole, toss meat mixture with olive oil.
Bake uncovered for 15 minutes, then add onions and mushrooms and toss. Continue to bake uncovered for another 15 minutes. Stir and add celery, potatoes, carrots, water and tomato sauce. Mix well. Cover and bake at 350°F/180°C for 2 – 2½ hours.
Steam broccoli, peas or green beans separately and add just before serving so they retain their vibrant green color.