Preheat the oven to 375°F (190°C).
In a large oven-safe skillet, heat olive oil over medium heat. Sauté the diced onion until translucent, about 5 minutes.
Add minced garlic to the skillet and cook for an additional minute until fragrant but not burnt.
Stir in the orzo and mix well to coat it in the aromatics, cooking for about 2 minutes.
Pour in the vegetable broth and season with salt and pepper. Bring to a simmer.
Remove from heat and stir in the frozen peas and crumbled feta cheese.
Transfer the skillet to the preheated oven. Bake for 25-30 minutes, or until the orzo is cooked through and the top is golden.
Remove from the oven and allow to cool for a few minutes before serving.