Design a gourmet hamburger using mixed-media techniques. The hamburger features intricate layers of vibrant ingredients, including glossy lettuce, juicy tomatoes, melted cheese, and a perfectly seared patty, with a toasted bun sprinkled with sesame seeds. Blend photorealistic textures with abstract, collage-style backgrounds and subtle 3D rendering for depth. Use a warm, vibrant color palette emphasizing golden yellows, rich reds, and earthy browns. The background should incorporate soft brush strokes and pastel patterns to create an artistic yet appetizing ambiance