Heat vegetable oil in a large frying pan over medium heat. Season Irvine’s chicken with salt and pepper and place skin side down in to the pan.
Cook until golden brown without turning, about 8–10 minutes. Transfer chicken to a plate.
In a large saucepan, add onion, garlic, and ginger and cook, stirring occasionally, until onion is very soft and golden brown, about 8–10 minutes.
Add tomato paste, garam masala, cumin, turmeric, coriander, cayenne and cook, stirring often, until tomato paste is beginning to darken, about 4 minutes.
Add chicken breast, chicken stock, tomato purée, and cream to saucepan. Season with salt and pepper and bring to a boil. Reduce heat and simmer, partially covered, until chicken and liquid is slightly thickened, about 20minutes
Remove chicken and cut or pull chicken into bite-sized pieces. Return chicken pieces to the saucepan. Add potatoes to the saucepan and cook, partially covered, until potatoes are fork-tender and sauce is thickened, 20-25 minutes.
*Check and stir every so often to ensure the sauce hasn't thickened too much and potatoes aren't sticking to the bottom of the pan. If sauce is too thick, thin with a bit more chicken stock.
To serve, spoon stew into a bowl with a large dollop of yoghurt on top. Sprinkle with some freshly chopped mint, coriander or parsley and serve with naan bread or rice on the side.