From Sahih Muslim (Hadith 5326):
Anas b. Malik reported that a person invited Allah's Messenger (ﷺ) to a meal. I also went along with him. He brought soup containing pumpkin. Allah's 'messenger (ﷺ) ate that pumpkin with relish. He (Anas) said:When I saw that I began to place it before him, and did not eat it (myself). Anas said: It was since then that pumpkin was always my favourite (food)
Reference: Muslim 5326