Cover the saucepan and turn the burner to medium-high so the water continues to boil gently. Steam the squash until you can easily pierce the squash with a fork or the tip of a knife. Thin slices or small chunks generally steam in 4 to 5 minutes, while a whole squash may take 10 to 12 minutes. Remove the steamer basket. Let the squash drain, then serve it hot or incorporate it into recipes such as squash casserole. If you don't plan to serve the squash immediately, store it in the refrigerator and use it within three to four days.