Green rhubarb pies. It’s one of the fond food memories I have from living in Pittsburgh as a kid. My friend’s mom would pay a visit to her garden and later resurface with a sweet-tart pie that made me pucker with every bite. Since rhubarb was a foreign ingredient in my family’s kitchen, her green pies were all I knew. It wasn’t until I was in my late twenties before I discovered that rhubarb is most commonly red. About five years ago, I introduced that red rhubarb into my kitchen.