This is adapted from Marcella Hazan's brilliant recipe for "Creamy Polenta." Because you were afraid of polenta! You demanded the right to not stir it so much! And we listened. We heard you.
Bring the water and salt to a boil in a 3-quart heavy saucepan (one that has a lid), then add the polenta in a thin stream, whisking (it will seem lumpy at first, but that's fine). Cook over moderate heat, whisking, for 2 minutes, then reduce the heat to low and cover the pot.
Cook the polenta at a bare simmer, stirring with wooden spoon for 1 minute after every 10 minutes of cooking, for 45 minutes total (I set the timer for 10 minutes, then make a littler mark on a pad to keep track of how many times I've done this; it sounds more complicated than it is). Remove the polenta from the heat and whisk in the butter and cheese until incorporated.
For the asparagus: In a medium/smallish pan, bring the water, butter and salt to a simmer over medium heat and add the asparagus. Cook uncovered, stirring occasionally at first and then more often, until the asparagus is tender and the liquid is more or less evaporated to a glaze, around 4 minutes (if the water evaporates before the asparagus is cooked, add another tablespoon).
Add a big squeeze of lemon and a grinding of black pepper and serve over the polenta.