豆腐 is tofu, and 湯 means hot water, making it tofu you've put in hot water, aka boiled tofu.
This is a jukugo word that uses the on'yomi readings of 豆腐 and the kun'yomi reading of 湯. You should be able to read this on your own. Will of course help to know 豆腐 as well.
At first, I just tried the boiled tofu out of curiosity, and then I grew to like it.