Wash and trim the woody ends off the asparagus bunches, then cut them into 2-inch pieces for even cooking. Trim the green beans and cut them to similar lengths. Freshly mince the garlic cloves and set aside. Toast the pine nuts in a dry skillet over medium heat for 2-3 minutes, stirring frequently until fragrant and lightly golden, then transfer to a plate to cool. Zest the lemon and juice it into a small bowl.

Bring a large pot of salted water to a rolling boil. Add the asparagus and green beans together and cook for 10 minutes until they're tender-crisp and bright green. Drain well in a colander, shaking off excess water—this step ensures the vegetables cook evenly and removes any bitterness while maintaining their vibrant color.

Melt the butter in a large skillet over high heat and let it foam slightly—I like using Kerrygold because its rich flavor really shines through in a simple dish like this. Add the blanched vegetables from Step 2 and sauté for 3 minutes, tossing occasionally, to get a light golden color on the edges and develop more complex flavors. Lower the heat to medium, add the minced garlic from Step 1, and cook for another 2-3 minutes, stirring frequently, until the garlic becomes fragrant and releases its oils without burning.

Remove the skillet from heat and pour in the lemon juice from Step 1, along with the red pepper flakes. Toss everything together gently to coat the vegetables evenly with the bright, tangy sauce. The heat from the pan will warm the lemon juice without cooking off its fresh acidity.

Transfer the sautéed asparagus and green beans to a serving dish. Top with the toasted pine nuts from Step 1 and scatter the lemon zest over everything just before serving for maximum brightness and crunch.