To transform the given sentence into one that starts with "What I should," you need to rephrase it while maintaining the original meaning. Here's the process:

1. Identify the main idea of the sentence: You want someone to take you out to dinner.
2. Start the new sentence with "What I should."
3. Follow with the rest of the sentence in a way that makes sense.

The original sentence is: "I should like someone to take me out to dinner."

Rephrased sentence: "What I should like is for someone to take me out to dinner."

So, the complete sentence is: "What I should like is for someone to take me out to dinner."

This maintains the original meaning while starting with "What I should."