John McKenzie's quite right. Don't over cook 'em.
My dear departed old Mum used to boil sprouts til all the crunch had gone, and then give 'em another hour to be sure they were totally inedible.
On thinking about it, she did that to all the vegetables she cooked, apart from potatoes.She wasn't very good at cooking savoury meals.
Her apple pie was really good, she just didn't understand vegetables, or meat.