1.In a medium bowl, combine the chicken with the mustard, juice, oil, rosemary and garlic. Place the chicken on a heated, oiled griddle (or barbecue or grill); cover chicken loosely with foil. Cook about six minutes on each side or until browned and cooked through.
2.In a medium pan of boiling water, add the potatoes and simmer, uncovered, until just tender. Add spinach, simmer, uncovered, until it is just wilted; drain.
3.Add the butter to the potato mixture in the pan and toss gently until the butter is melted.
4.Serve the chicken with the potato mixture and lemon wedges.
This recipe is best made close to serving.Note