This delicious recipe is courtesy of Alexis Stewart.
In a large bowl, whisk together vinegar, oil, sugar, and dill. Add cucumbers and onion, season with salt and pepper, and toss until well combined; set aside.
Fill a large pot with water and bring to a boil. Add salt and return water to a boil. Prepare an ice-water bath; set aside. Place asparagus in boiling water; cook until just tender, 2 minutes. Using a slotted spoon, transfer asparagus to ice-water bath for 1 minute, remove and pat dry; transfer to cucumber mixture. Add beans to the boiling water, and cook until just tender, 3 minutes. Using a slotted spoon, transfer beans to the ice-water bath for 1 minute, remove and pat dry. Transfer beans to cucumber mixture along with hearts of palm, tomatoes, and lettuce. Season with salt and pepper; toss until well combined.