Start by preheating your oven to 350 degrees. Pound chicken breast between two pieces of saran wrap or wax paper for a uniform thickness. Melt 1 stick of butter (I never said this was healthy). Combine butter with 3 heaping tablespoons of Dijon mustard. Finely chop 1-2 cups of pecans. Make an assemble line like the picture below. Dip chicken into the butter mixture then coat with pecans and set aside.
Heat 2 tablespoons of butter and canola oil in a pan over medium heat. Add chicken and cook until browned on each side. Remove chicken from pan and place on a baking sheet (don't worry if some or alot of the pecans fall off). Bake for 20-30 minutes or until done. In the pan that you cooked the chicken in add 2/3 - 1 cup of sour cream, stir in 2-3 tablespoons of Dijon, salt and pepper. Spoon on top of the chicken and enjoy.