In a large skillet, heat olive oil over medium heat. Sauté onion and carrots for 5–7 minutes until soft.
Add garlic and cook 1 minute more.
Add the ground lamb, breaking it up with a spoon. Cook until browned. Drain excess fat if needed.
Stir in tomato paste, Worcestershire sauce, thyme, and rosemary.
Season with salt and pepper.
Sprinkle flour if using, stir, then add broth.
Simmer for 5–10 minutes until the mixture thickens slightly. Stir in peas. Remove from heat.