In a narrow dish, whisk together flour, salt, black pepper, garlic powder, onion powder, and paprika. Dredge cube steaks in flour mixture on both sides and shake off excess.
Heat oil in a large skillet over medium high heat. Add in dredged cube steak 1-2 pieces at a time. Sear for 3 minutes on one side and flip over. Sear an additional 3 minutes until golden brown. Remove from pan on to a plate. Cook remainder dredged cube steaks.
After all cube steaks are browned and removed, in same skillet over medium high heat, add 1 TBS cooking oil, cut carrots, celery, and onions. Season with additional 1/4 tsp each of salt, black pepper, garlic powder, onion powder, and paprika. Add in canned diced tomatoes and mix well.
Pour mixture into crockpot. Add in browned cube steaks and submerge them into the liquid and cover with the vegetables.
Cover with lid and cook on low for 8-10 hours or on high for 6-8 hours until steaks and vegetables are fork tender.
Best served over cooked rice, mashed potatoes, or egg noodles.