How to Make It
In a blender, combine the olives with 1/3 cup of olive oil and puree. Add the garlic, rosemary, lemon zest and vinegar and puree. If the black-olive oil is too thick, add a little more olive oil.
Light a grill or preheat a grill pan. Brush the radicchio with 1 tablespoon of the remaining oil and grill over high heat, turning, until wilted, 5 minutes. Transfer to a bowl and toss with 2 tablespoons of the oil, the shallot and thyme. Season with salt and pepper; keep warm.
In a bowl, mix the cumin, paprika and the remaining 1 tablespoon of oil. Add the lamb; turn to coat. Season with salt and pepper. Grill over high heat until medium rare, 2 minutes per side. Transfer to a plate; let stand for 5 minutes. Thread each lamb cube onto a small skewer or sturdy toothpick. Arrange the radicchio on a platter, top with the lamb and serve with the black-olive oil.