Add the butter and olive oil to a large skillet and heat over medium-high, until the butter is melted. Swirl the pan to mix the two.

Add the onions and cook, stirring occasionally, for 8-10 minutes, until browned at the edges. Reduce heat to low and cook for 20 minutes, stirring occasionally.

Meanwhile, heat a saucepan of water and cook the orzo to al dente. Drain.

When the onions are soft, transcusent and golden brown, sprinkle with salt. Then add the orzo, white wine and parmesan, stirring well to combine. Cook for about 10 minutes, stirring frequently.

Serve with a sprinkling of chopped parsley.