Bring 4 quarts water to boil in large pot. Fill large bowl halfway with ice and water. Add green beans and 1 tablespoon salt to boiling water and cook until crisp-tender, about 6 minutes.
Drain green beans and place in ice bath to cool. Drain again, transfer to salad spinner, and spin dry. (Blanched, shocked, and dried green beans can be refrigerated for up to two days.)
Whisk shallot, mustard, lemon zest and juice, garlic, and 1 1/2 teaspoons salt together in large bowl. Slowly whisk in oil until incorporated.
Toss radishes, dill, and green beans with vinaigrette and let sit for 30 minutes or up to 2 hours, stirring occasionally. Stir almonds into salad. Season with salt and pepper to taste. Serves 8.
Note: If you don't own a salad spinner, lay the green beans on a clean dish towel to dry in step 1. Our favorite Dijon is Grey Poupon Dijon Mustard. Substitute parsley for the dill, if you like.