How to Make It
Heat the butter and oil in a large skillet or saucepan over medium heat. Add the onion and sauté until translucent, 3 to 4 minutes.
Add the rice and stir until coated. Add the wine and stir until all the liquid is absorbed. Add 1 cup of the broth and cook until absorbed, stirring occasionally.
Add the remaining broth ½ cup at a time, waiting until each portion is absorbed before adding the next. Continue until the rice is cooked al dente, about 35 minutes. Stir in the Parmesan, 1 teaspoon salt, and ¼ teaspoon pepper.
Meanwhile, puree 2 cups of peas in a blender or food processor.
Before serving, stir the peas into the rice until fully incorporated, then fold in remaining whole peas. Garnish with the mint, if desired.