1/4 ounce jalapeno, seeded, ribs removed, and finely chopped
2 ribs celery, trimmed and cut into 1/4-cubes, leaves reserved
Zest and juice of 1 orange (about 6 tablespoons juice)
2 tablespoons sherry or red-wine vinegar
1 tablespoon honey
Coarse salt and freshly ground pepper
2 firm pears, such as Bosc, peeled, cored, and quartered
2 tart apples, such as Fuji, peeled, cored, and quartered
1/2 teaspoon ground ginger
2 tablespoons dark-brown sugar
Zest and juice of 1 lemon (about 3 tablespoons)
1 small red onion, peeled and cut into 1/2-inch rounds
Olive-oil cooking spray
Combine jalapeno and celery in a large bowl; set aside. In a small bowl, combine orange juice, sherry, and honey; season with salt and pepper. Pour orange mixture over jalapeno-celery mixture. Add orange zest; toss to combine. Set aside.
In a medium bowl, combine pears, apples, ginger, sugar, and lemon juice; set aside. Spray a grill pan with cooking spray. Heat over medium-high heat until hot but not smoking. Grill onion rounds, basting with a little liquid from pear-apple mixture. Cook each side until softened and slightly charred, 3 to 5 minutes per side. Transfer onions to a cutting board; cut into 1/4-inch cubes. Add to jalapeno-celery mixture.
Grill apple and pear quarters in batches, until golden brown on each side, basting with collected juices in bowl, 2 to 5 minutes per side. Transfer to a cutting board; cut into 3/4-inch cubes. Add to jalapeno-celery mixture along with juices. Chop celery leaves; add to jalapeno-celery mixture along with lemon zest. Stir to combine. Let sit at least 1 hour at room temperature. Season to taste.