The Greasy Strangler tastes different to all the other films in the kitchen of Sundance programming director Trevor Groth. It is like giving cinema-goers a messy bowl of jelly instead of popcorn or M&M’s. It is an unpretentious and puerile new flavour and experience.

British director Jim Hosking and scriptwriter Toby Harvard took very high risks sending their first feature to Sundance in the US. First, they are not American Indies; they are also not famous. The Greasy Strangler, a story about a greedy clumsy dad and his alike maladjusted son, was on six screening rooms in last January at the original Sundance Film Festival, a relatively low tally given the dimensions of the event.

It received mixed reactions from the public and critic, and stirred a lot of debate and controversy. It is an uncomfortable, visceral and nauseating ride. Below is the recipe used by the director in case you want to make a greasy film at home.

Recipe: How to bake a dirty movie and become a hit at the Sundance Film Festival

Ingredients

• 175 g (6 oz) of actors you personally know;
• 35 vintage and weird clothes;
• 175 (6 oz) of props, including a small fake penis;
• Pitiful characters;
• 4 tbsp olive oil (avoid the virgin varieties);
• 40 g (1½ oz) real locations in Los Angeles, including a house that hasn’t been cleaned in 50 years;
• 1 producer that has worked with Ben Wheatley (High-Rise, 2015);
• A spice of melancholia and bleakness; and
• A spoonful of horror.

Method

1. Scriptwriters Jim Hosking and Toby Harvard joined forces to write a movie about characters people don’t see everyday.
2. They think about Big Ronnie (Michael St. Michaels) and his son Brayden (Sky Elobar) and preheat the oven to 180C.
3. Both father and son are “funny, sweet, clumsy, interesting people”, who organised a disco tour in the city, says Hosking.
4. Then they meet a “manipulative” – and fat – sexy woman in the tour, and they begin a love triangle.
5. Beat together father and son. They fight for the same woman; father humiliates son and threatens him with eviction.
6. Put father in a separate mixing bowl. Apart from doing the disco tour, Big Ronnie is also a serial killer in his spare time. The greasy strangler is ready.
7. Leave the triangle to cool in the haunted house. The tension grows as if someone had added yeast.
8. Serve it hot.

Don’t worry if in the end neither father nor son learn anything. There’s a big chance the cake will deflate and be very unsavory. That’s just the way the cookie crumbles!

Observation: The Greasy Strangler was the dirtiest movie screening at Sundance London last June. The least you know, the better. It is out now in cinemas across the UK.