Bring a large pot of water to a boil (8 to 12 cups/2 to 3 L). Salt generously (about 1½ tablespoons kosher salt).
Cut the green beans in half on a bias (if they are skinny and small, keep them whole). If you are using regular green beans, cut them into 2-inch (5 cm) pieces.
Slice the trimmed asparagus on a sharp bias into 1½- to 2-inch (4 to 5 cm) pieces. Fill a large bowl with ice water.
Add the green beans to the pot. Once the water returns to a boil, cook for 2 minutes (3 minutes for regular green beans). Add the asparagus and, once the water returns to a boil, cook for 2 minutes.
Use a slotted spoon to immediately transfer the veg to the ice bath. Once cold, drain, transfer to dish towels, and dry as well as you can so the vegetables don’t taste watery.
Transfer to a large serving bowl, add the edamame, and sprinkle with a few pinches of kosher salt.
In a small bowl, combine the pistachios and basil. Sprinkle with a few pinches of flaky salt.
In a medium skillet, heat the olive oil over medium-low heat. Once it is warm but not hot, add the garlic and cook, swirling the pan or stirring frequently and separating the slices, until it just turns golden (don’t wait until it browns), 2 to 2½ minutes.
Add the lemon zest and pepper flakes and cook for 30 seconds, swirling often. Season with a pinch of kosher salt and black pepper and remove from the heat.
Drizzle the warm garlic oil on top of the asparagus and beans. Add 2 tablespoons lemon juice, ¼ teaspoon flaky salt, and several cracks of black pepper and toss well. Add the pistachio-basil topping and toss to coat.
Taste, adding a drizzle of olive oil or more lemon juice as desired.