1. Bring vinegar, juice, and zest to a rapid simmer in a small saucepan, and cook until reduced to 1/4 cup, about 5 minutes. Let cool slightly; remove zest, and discard. Whisk in 2 tablespoons extra-virgin olive oil.

2. Preheat a grill or grill pan to medium heat. Toss kale and radicchio with remaining 1/4 cup extra-virgin olive oil and 2 teaspoons salt; season with pepper. Separate out radicchio, and grill, turning occasionally, until tender and lightly charred in places, 8 to 10 minutes. Transfer to a large bowl, and toss with 1 tablespoon dressing. In 2 or 3 batches, grill kale, keeping it piled on grill and turning often to prevent too much charring, until wilted, about 6 minutes per batch. Transfer each batch as grilled to bowl with radicchio, and toss each batch with 1 tablespoon dressing. When all kale has been added, toss with any remaining dressing and the almonds until thoroughly coated. Transfer to a large platter, and drizzle with 1 tablespoon orange olive oil or more to taste.