Heat milk in a pan. Add soaked ground rice and stir continuously to avoid any lumps. When the rice milk mixture thickens, add sugar and mashed condensed milk solids. Stir again. In a bowl, mix some fresh cream, cashew nut paste, cardamom powder, and kewra water. Add this mixture to the rice milk blend in the pan. Cook till the mixture thickens. Transfer shir berenj to a serving bowl. Garnish with chopped mixed nuts and rose petals.