To say ‘What are you eating?’ in Spanish, you would say ‘¿Qué estás comiendo?’
This phrase is made up of three parts: ‘qué’ meaning ‘what’, ‘estás’ which is the second-person singular form of the verb ‘estar’ (to be), and ‘comiendo’ which is the gerund form of ‘comer’ (to eat). This structure is commonly used to ask someone about their current activity, and in this case, it specifically refers to eating.
Spanish is a rich language with various ways to express ideas, and asking someone what they are eating can lead to interesting conversations about food!