Mix mayo, EVOO, grated garlic and chopped fresh rosemary; season. Thread skewers with whole baby bell peppers, cooked baby potatoes and strip steak cubes; season. Grill over medium-high, turning occasionally and brushing with mayo mixture, until potatoes and peppers are charred in spots and steak is cooked to desired doneness, about 8 minutes for medium-rare. Serve with remaining mayo.
