Preheat oven to 350F
Spread the walnuts on a baking sheet and toast for 5 minutes.
Let cool and coarsely chop.
Zest the two lemon rinds and then squeeze the juice.
In a medium saucepan, bring 1 inch of salted water to a boil. Add the green beans and cook until just tender, about 6-8 minutes.
Using a slotted spoon, transfer the beans to a colander under running cold water. Then add the wax beans to the boiling water, cook for 4-6 minutes and transfer them to the colander as well.
In a large bowl, mix the lemon juice, zest, jalapenos, chile, and maple syrup. Add the beans and olive oil and toss.
Stir in the walnuts and herbs, season with salt and pepper, and refrigerate for an hour. You can make this a day ahead too and just season again before serving.