Wash lentils in a fine mesh strainer. Place in pot of 1-quart cool, salted water and bring to a simmer. Cook until tender, drain and reserve on a sheet pan.
Clean artichokes by removing the tough outer leaves and stem. Cook in salted water with 2 lemon halves. Bring to a simmer and cook until tender, but not falling apart.
Shock artichokes in ice water and when cooked, drain and sprinkle with lemon juice and olive oil. Reserve.
Rough cut spinach and reserve.