Chef Vikas Khanna on Monday shared a post to mourn the death of his sister, Radhika Khanna. Sharing a photo, Khanna wrote, "My soulmate left me today...She fought like a champion for years with Lupus, aHUS, renal failure. But today due to multiple organ failures, my best friend passed away in my arms. Loveeeee you Radha forever & forever. RIP."