Today, March 14, is Pi Day, the day of the year when math nerds everywhere honor π, the never-ending number (3.14159265359…) that corresponds to the ratio of the circumference of a circle to its diameter. With a family tree full of engineers (and others in math-related fields), Pi Day is acknowledged and celebrated around here.

The featured recipe for π day this year is a savory pot pie. Ground beef, vegetables, and cheese are sandwiched between two layers of flaky puff pastry. Along with potatoes, the vegetables in this pot pie includes rapini. Rapini (or broccoli rabe) is a cruciferous green vegetable that looks like broccoli but with a smaller head and more leaves. The leaves, buds, and stems are all edible. Rapini, particularly associated with Mediterranean cuisine, is known for its strong flavor and slightly bitter taste, perfectly balancing the beef and potato in this dish.

Beef, Rapini, & Provolone Pot Pie (adapted from saveur.com) Time Required: about 90 minutes, Prep Time: Serves: 8

Ingredients:

• 1 tablespoon extra-virgin olive oil
• 1 small onion, finely diced
• 10 ounces Yukon Gold potatoes, peeled and cut into 1/4-inch cubes
• kosher salt and freshly ground black pepper
• 2 pounds ground beef
• 1/4 cups fresh lemon juice
• 2 large cloves garlic, finely chopped
• 8 ounces provolone, shredded, plus more for serving
• 3 ounces (1/2 bunch) rapini (broccoli rabe), stalks and leaves trimmed and cut into 3/4-inch pieces
• 1/2 teaspoon crushed red chile flakes
• 2 sheets all-butter puff pastry, cold, thawed in the refrigerator for at least 3 hours
• 1 large egg, beaten with 1 teaspoon water

Instructions:

Preheat the oven to 375°F. In a large skillet over medium-high heat, add the oil, onion, and potato, and season with salt to taste. Cook, stirring, until the veggies are warmed and sizzling, about 3 minutes.

Add the beef, 1-1/2 teaspoons salt, and a generous pinch of black pepper. Cook, breaking up the beef with a spatula, until the beef is no longer pink and some of the liquid has evaporated, about 15 minutes.

Stir in the lemon juice, garlic, and chile flakes then continue cooking until the lemon juice has mostly evaporated, about 2 minutes more.

Turn off the heat and stir in the cheese and rapini until everything is evenly distributed. Taste and adjust the seasoning with more salt, pepper, and chile flakes as needed. Transfer the mixture to a large, wide bowl and let it cool completely.

When the mixture is cooled, retrieve the puff pastry from the refrigerator. On a lightly floured surface, roll out 1 sheet of the pastry to about 1/8-inch thickness and trim it into a 12-inch round. Transfer the pastry to a 10-inch cast-iron skillet or deep-dish pie plate.

Roll the remaining sheet to about 1/8-inch thickness and trim into a 12-inch round. Using a slotted spoon, transfer the beef mixture to the pastry-lined skillet.

Lightly brush the edges with some of the egg mixture, then place the remaining round of pastry on top. Press the edges to seal, trim all but 1/2-inch of the overhang, and crimp the edges to seal it. Lightly brush the top of the pot pie with more of the egg mixture. Cut an “X” in the center of the pie for ventilation. Lightly sprinkle the top with salt and black pepper.

Bake the pot pie until the top crust is golden brown and puffed, and the bottom crust is set and easily pulls away from the sides of the skillet, about 45–50 minutes. Transfer the skillet to a rack and let it cool for 10-15 minutes, topping with additional shredded provolone. Slice the pie into wedges.

Serve.

Who knew Math could be so delicious?!  ~Linda

Beef, Rapini, & Provolone Pot Pie (adapted from saveur.com) Time Required: about 90 minutes, Prep Time: Serves: 8

Ingredients:

• 1 tablespoon extra-virgin olive oil
• 1 small onion, finely diced
• 10 ounces Yukon Gold potatoes, peeled and cut into 1/4-inch cubes
• kosher salt and freshly ground black pepper
• 2 pounds ground beef
• 1/4 cups fresh lemon juice
• 2 large cloves garlic, finely chopped
• 8 ounces provolone, shredded, plus more for serving
• 3 ounces (1/2 bunch) rapini (broccoli rabe), stalks and leaves trimmed and cut into 3/4-inch pieces
• 1/2 teaspoon crushed red chile flakes
• 2 sheets all-butter puff pastry, cold, thawed in the refrigerator for at least 3 hours
• 1 large egg, beaten with 1 teaspoon water

Instructions:

Preheat the oven to 375°F. In a large skillet over medium-high heat, add the oil, onion, and potato, and season with salt to taste. Cook, stirring, until the veggies are warmed and sizzling, about 3 minutes. Add the beef, 1-1/2 teaspoons salt, and a generous pinch of black pepper. Cook, breaking up the beef with a spatula, until the beef is no longer pink and some of the liquid has evaporated, about 15 minutes. Stir in the lemon juice and garlic, and continue cooking until the lemon juice has mostly evaporated, about 2 minutes more.

Turn off the heat and stir in the cheese, rapini, and chile flakes until everything is evenly distributed. Taste and adjust the seasoning with more salt, pepper, and chile flakes as needed. Transfer the mixture to a large, wide bowl and let it cool completely.

When the mixture is cooled, retrieve the puff pastry from the refrigerator. On a lightly floured surface, roll out 1 sheet of the pastry to about 1/8-inch thickness and trim it into a 12-inch round. Transfer the pastry to a 10-inch cast-iron skillet or deep-dish pie plate. Roll the remaining sheet to about 1/8-inch thickness and trim into a 12-inch round. Using a slotted spoon, transfer the beef mixture to the pastry-lined skillet. Lightly brush the edges with some of the egg mixture, then place the remaining round of pastry on top. Press the edges to seal, trim all but 1/2-inch of the overhang, and crimp the edges to seal it.

Lightly brush the top of the pot pie with more of the egg mixture. Cut an “X” in the center of the pie for ventilation. Lightly sprinkle the top with salt and black pepper.

Bake the pot pie until the top crust is golden brown and puffed, and the bottom crust is set and easily pulls away from the sides of the skillet, about 45–50 minutes. Transfer the skillet to a rack and let it cool for 10-15 minutes, topping with additional shredded provolone, then slice the pie into wedges and serve.