Combine all-purpose flour, garlic powder, salt, and black pepper in a mixing bowl. Toss stewing beef cubes in the mixture.

Heat olive oil in a Dutch oven over medium-high heat. Brown the beef in batches for 3-4 minutes.

Sauté chopped onion in the same pot for about 3 minutes until soft and translucent.

Deglaze the pot with beef broth and optional red wine, scraping any browned bits.

Return the browned beef, add chopped potatoes, carrots, celery, tomato paste, and dried rosemary. Cover and simmer for 1 to 1.5 hours.

Mix cornstarch with cold water to create a slurry. Gradually add to the stew while stirring. Simmer until thickened for 5-10 minutes.

Stir in frozen peas and cook for another 5 minutes until heated through. Adjust seasoning if necessary.