In a cast iron/ heavy bottom skillet – heat olive oil and add the finely chopped onions. Cook until transparent. Add the garlic and cook for 2 minutes.
Add the orzo and mix well. Season with salt and add the pesto. Mix well.
Add 1 cup of stock and mix well, let it simmer for 5-8 minutes. Orzo will absorb not just the stock but also some flavors of the pesto. You needn’t keep stirring like in a risotto, and you can stir occasionally.
Add another 1/2 cup of the stock and stir some more. Cook for another 10 minutes until the orzo is completely cooked. Use the remaining 1/2 cup (and more) if need be!
Mix in chilli flakes.
Dish out in a shallow bowl, and top with torn-apart burrata cheese and fresh basil leaves.