In a large skillet, heat the olive oil over medium heat. Add the diced onion and cook until translucent, about 3-4 minutes. Stir in the minced garlic and cook for an additional 1 minute until fragrant.

Add the ground beef to the skillet, breaking it apart with a spatula. Cook until browned and no longer pink, about 5-7 minutes. Drain any excess fat if necessary.

Stir in the orzo pasta, diced tomatoes (with their juice), beef broth, Italian seasoning, salt, and black pepper. Bring the mixture to a boil.

Once boiling, reduce the heat to low, cover the skillet, and simmer for about 10-12 minutes, or until the orzo is tender and has absorbed most of the liquid. Stir occasionally to prevent sticking.

Add the frozen peas and stir to combine. Cook for an additional 2-3 minutes until the peas are heated through.

Remove from heat and stir in the grated Parmesan cheese until melted and creamy. Garnish with chopped parsley before serving.