Slate recommendation is a technique commonly used on streaming platforms and e-commerce sites to present multiple items together. A significant challenge with slate recommendation is managing the complex combinatorial choice space. Traditional methods often simplify this problem by assuming users engage with only one item at a time. However, this simplification does not reflect the reality, as users often interact with multiple items simultaneously. In this paper, we address the general slate recommendation problem, which accounts for simultaneous engagement with multiple items. We propose a generative approach using Diffusion Models, leveraging their ability to learn structures in high-dimensional data. Our model generates high-quality slates that maximize user satisfaction by overcoming the challenges of the combinatorial choice space. Furthermore, our approach enhances the diversity of recommendations. Extensive offline evaluations on applications such as music playlist generation and e-commerce bundle recommendations show that our model outperforms state-of-the-art baselines in both relevance and diversity.