In a large skillet, heat the vegetable oil over medium heat. Add the diced onion and sauté until translucent, about 5 minutes.
Stir in the minced garlic and grated ginger, cooking for an additional 1-2 minutes until fragrant.
Add the ground beef to the skillet, breaking it up with a spoon. Cook until browned, about 5-7 minutes. Drain excess fat if necessary.
Sprinkle in the curry powder, cumin, coriander, turmeric, and red pepper flakes. Stir well to coat the beef and cook for 1-2 minutes to toast the spices.
Pour in the diced tomatoes with their juice and the beef broth. Stir to combine and bring to a simmer.
Reduce the heat to low and let the curry simmer for 15 minutes, stirring occasionally.
Add the frozen peas and cook for an additional 5 minutes until heated through. Season with salt and pepper to taste.
Serve the curry over cooked rice or with naan, garnished with fresh cilantro if desired.