How to Make It
Preheat a cast-iron grill pan. In a large bowl, whisk the yogurt with the 6 tablespoons of olive oil, the lemon juice and mustard. Season with salt and pepper.
Working in 2 batches, grill the kale over moderate heat, turning, until lightly charred, about 3 minutes per batch. Transfer to a work surface. Discard the ribs and chop the kale. Add to the yogurt dressing and toss to coat evenly.
Brush one side of each bread slice with oil and grill oil side down until golden, about 5 minutes. Rub the grilled sides with the cut garlic. Top with the kale and cheese and arrange on a platter. Serve warm.