Heat olive oil in a deep skillet or Dutch oven over medium heat. Add diced onion and cook until translucent.

Stir in minced garlic and cook for another 30 seconds.

Add ground beef and cook until browned, breaking it apart with a spatula. Season with salt and pepper.

Stir in tomato paste and crushed tomatoes. Let simmer for 2–3 minutes.

Lower the heat and add the heavy cream, letting it simmer until thickened.

Stir in the uncooked orzo and water. Cover and simmer for 10–12 minutes, stirring occasionally.

Once orzo is tender, turn off the heat. Stir in mozzarella and fresh basil. Let it sit for 2 minutes before serving.