Sentence:  First, marinate the tofu. In a bowl, whisk the kecap manis, chilli sauce, and sesame oil together. Cut the tofu into strips about 1cm thick, mix gently (so it doesn't <WSD>break</WSD>) with the marinade and leave in the fridge for half an hour. 
Meaning of the word marked with <WSD> tags:  To separate into two or more pieces, to fracture or crack, by a process that cannot easily be reversed for reassembly.