Fill a kettle and boil it. Peel and finely chop the onion. Rinse the peppers and halve them. Scoop out the seeds and white bits. Roughly chop them. Peel and chop the potatoes into chunks. Strip the leaves from half the thyme stalks.
Fill a pan with hot water from the kettle. Add a pinch of salt. Pop the potatoes in the pan and bring to the boil. Cover. Simmer for 15-20 mins till they feel soft when pressed with a fork.
Heat a glug of olive oil in a pan. Add the chicken. Stir and fry for 5 mins till browned. Pop on a plate and put to one side.
Add the onion and peppers to the pan. Stir and fry for 5 mins till the veg look soft and glossy.
Add the chicken back into the pan with any juices. Add the chopped tomatoes, most of the thyme leaves and a pinch of the smoked paprika. Pop on a lid. Simmer over a lowish heat for 10 mins till the stew has thickened slightly.
Drain the potatoes. Tip them back into the empty pan. Add half the crème fraîche and some seasoning. Mash the potatoes till they're smooth.
Taste the chicken paprikash and adjust the seasoning if you think it needs it. Serve with the mash, sprinkled with the rest of the thyme leaves, and the remaining crème fraîche sprinkled with a pinch of the smoked paprika.