How to Make It
In a small bowl, mix the butter with the chopped squash blossom petals.
Prepare an ice bath. In a large pot of salted boiling water, blanch the green and wax beans until crisp-tender, about 3 minutes. Using a slotted spoon, transfer the beans to the ice bath to cool completely. Drain, pat dry and halve the beans lengthwise.
Meanwhile, return the water to a boil. Cook the pasta until al dente. Drain, reserving 1 1/2 cups of the cooking water.
In a large skillet, melt the squash blossom butter. Add the pasta and pasta water and bring to a boil over moderately high heat. Add the beans and cook, stirring, until the sauce is thickened and the beans are heated through, about 2 minutes. Add the chives, the chopped basil, the 2 tablespoons of cheese, and the lemon zest and lemon juice; season with salt and pepper. Transfer the pasta to shallow bowls and garnish with more cheese, squash blossom petals and basil leaves; serve.