The milk was not reduced enough, so there is too much water. Boil it down to half and add khoya or milk powder for body.

Can I make kulfi without kulfi moulds?

Yes. Use paper cups with a stick pushed in once half-set, or freeze it in a loaf tin and cut slices.

Kulfi Recipe (Pakistani, Step by Step)

Name: Kulfi
Prep time: 8 h 15 min
Cook time: 1 h
Total time: 9 h 15 min
Cuisine: Pakistani
Ingredients: 6 cups Milk, full-fat, about 1.5 litres; ½ cup Sugar, adjust to taste; ½ cup Khoya (mawa), crumbled, about 100 g; 1 tbsp Cornflour, mixed with 3 tbsp cold milk; 6 pods Green cardamom (choti elaichi), seeds only, finely ground; 3 tbsp Pistachios (pista), finely chopped; 2 tbsp Almonds (badam), finely chopped; ¼ tsp Kewra water

Method

Bring the milk to the boil in a wide, heavy pan, then simmer on low-medium heat, stirring every couple of minutes and scraping the cream from the sides back in.
⏱ 40 min
When the milk has reduced to about half, add the sugar and crumbled khoya and stir until the khoya melts in.
⏱ 5 min
Stir in the cornflour mixture and cook, stirring constantly, until the milk thickens to the consistency of thin custard.
⏱ 5 min
Take off the heat and stir in the cardamom, most of the nuts and the kewra if using. Leave to cool completely, stirring now and then so no skin forms.
⏱ 30 min
Pour into kulfi moulds, small cups or one container, sprinkle the remaining nuts on top, cover tightly and freeze until completely firm.
⏱ 480 min
To unmould, dip the moulds in warm water for a few seconds or roll them between your palms, then slide the kulfi out. Slice and serve straight away.