In a big, shallow bowl, mix the flour, salt, and pepper.
In a large skillet, heat the butter and vegetable oil over medium-high heat until shimmering.
Working in batches, lightly dredge the chicken in flour and shake off the excess. Fry over medium-high heat for approximately 7 minutes; turn and fry for another 7 minutes. Cover the skillet with a lid and continue cooking over low heat for 25 minutes.
Meanwhile, in a food processor, pulse the garlic and walnuts until you get a wet sand-like texture.
When the chicken is tender and cooked all the way through, transfer it to a platter. Add the ground walnut mix to the pan and pour the milk. Season to taste with all the spices, add salt and black pepper to taste. Simmer over low heat for 5 minutes.
Return the chicken to the pan, mix well with the sauce. Add the chopped mint and simmer covered for 4 more minutes.
Notes
Serve this chicken with fried or mashed potato, roasted veggies, or a simple salad.