In a medium bowl, add the cider, lemon and honey and use a whisk to combine. Add the tomatoes and onion and toss to combine. Set aside to marinate for 30 minutes to 1 hour.
Prepare a medium-high charcoal fire, preheat a gas grill to medium-high, or heat a large grill pan over medium-high heat.
Coat the asparagus and corn with olive oil, using a silicone pastry brush. Grill over moderate high heat, turning occasionally, until tender and lightly charred, about 3 minutes for the asparagus and 6 minutes for the corn.
Transfer the corn and asparagus to a cutting board, and when warm enough to handle, cut the asparagus into 2-inch pieces, and use a corn stripper to remove the corn from the cob.
Add the asparagus, corn and basil to the marinated tomatoes and toss to thoroughly combine. Taste and season with salt and pepper.
