Why does my asparagus turn out too chewy?

When I make asparagus, I cut off the ends and boil them in water for about 5 minutes. I discard the ends, and add the other half of the (uncooked) asparagus into the pan with the same water for 8-10 minutes (medium high heat). Afterwards, I place the asparagus on a baking sheet, top with cheese, and put it in the oven at 350 degrees until the cheese melts. My question is.. Why do my asparagus come out too chewy/soggy? Am I cooking them for too long? What would you suggest I do differently to get the right texture? Thanks!