New Delhi, Jan. 30 -- THE PIZZA HUT in Plano, north of Dallas, looks much like any other. Cars draw up at the drive-through window. Inside the restaurant, staff slide pizzas out of the oven into cardboard boxes. But this restaurant is special: it is a laboratory for the chain's new ideas. And that means it is a place where the worlds of melted cheese and artificial intelligence (AI) collide.

Customers place orders by talking to a voice-enabled AI model. Machine-learning algorithms work out which orders the kitchen should make first. A screen shows AI-synthesised customer feedback from review sites and social-media platforms. Fast-food restaurants tend to have high staff turnover: new joiners here can query a chatbot to see how much of ea...