Heat the oven to 220C/fan 190C/gas 7. Make the pizza base following the pack instructions. Roll out to a rough, thin rectangle and put on an oiled baking sheet.
Spread a thin layer of crème fraîche over the surface, leaving a small border. Scatter over the onion, pancetta and thyme. Season really well. Bake in the top of the oven for 15-20 mins until the crust is crisp and golden.