Instead of a traditional brainstorming activity, why not engage teams in a match of vocabulary tennis?
Split the class into two teams. Teams stand in two lines facing each other. Give the topic or category e.g. food and nominate a student to ”serve”. They say a word connected to the topic, e.g. apple.
The student of the other team has then a chance to “return” the ball by saying a word that begins with the last letter of the first word, e.g. egg. Keep going, throwing the turns between students until one student takes too long to think, gets an answer wrong or says something that has been said previously. The team then loses and the other team gets a point.