Hump Day Movie: Mr. Frost (1990)
Here's a brief synopsis from wiki:
A police detective named Felix Detweiler visits the palatial French estate of Mister Frost, whose first name is never given, to investigate a report of a dead body. Frost, with very little prompting, cheerfully admits that he has many bodies buried in his yard.Frost is arrested and ultimately placed in an asylum, not having spoken a word for two years. During this time the police are unable to establish his identity. The detective leaves his job and becomes obsessed with Frost and the 24 corpses dug up from his garden. Frost's long silence is broken when he encounters Sarah Day, a doctor at the asylum. Frost refuses to speak with anyone but her, then tells Dr. Day that he is, in fact, Satan. He reveals that he plans to goad her into murdering him.
This came out about a year before Silence of the Lambs, but it is similar in style. It's a dialogue-driven film, filled with philosophical discussions between doctor and patient. It has a very early 90s/late 80s aesthetic, though, so be warned.
You can watch the trailer here. It's really awful, though, so it's no wonder the public's reception of this movie was tepid.