Combine squash, carrots, broth, and s&p in pan with tight fitting lid. Bring to boil uncovered, then reduce heat to low, cover, and let simmer for 30 mins.

Mash the mixture until smooth. It may still be runny. Add butter and stir to melt. Divide cheese into spoonfuls for better melting. Stir over low heat until cheese and butter are integrated into mash. Remove from heat and let stand for 5 mins before serving. Enjoy!