Preheat oven to 350°F Roll out pie crust and place in pie plate; set aside.
Heat a skillet over medium-high and saute chorizo, breaking into smaller chunks, for 4-5 minutes or until mostly cooked through. Add onion and cook until onion is soft and chorizo is cooked all the way through. Stir in beans.
Place cheese in crust then add onion, chorizo & bean mixture.
Beat eggs and milk together until slightly foamy then add salt and pepper. Pour into pie shell.
Bake until brown and puffed, about 50 minutes. Remove from oven and cool on wire rack for 15 minutes before cutting and serving.