01 - Heat butter and olive oil in a large, heavy-bottomed saucepan over medium heat. Add onion and sauté until translucent, about 3 minutes. Stir in garlic and cook for 1 minute more.
02 - Add Arborio rice and cook, stirring constantly, for 2 minutes until the grains are well coated and slightly translucent at the edges.
03 - Pour in the white wine. Stir and cook until almost completely absorbed.
04 - Add warm vegetable broth, one ladle at a time, stirring frequently. Allow each addition to be absorbed before adding the next. Continue until the rice is creamy and al dente, about 18–20 minutes (you may not need all the broth).
05 - Reduce heat to low. Stir in the Parmesan cheese and pesto until fully combined. Season with salt and pepper to taste.
06 - Remove from heat, cover, and let rest for 2 minutes.
07 - Serve immediately, garnished with extra Parmesan, basil leaves, and toasted pine nuts if desired.