In a food processor or blender combine all of the magic mustard sauce ingredients and blend until smooth.
Heat a wok or large skillet over high heat. Add the oil and when very hot (it should be just smoking), add chicken and season with salt and pepper. Spread the chicken in a single layer and cook until all sides are golden brown and the chicken is cooked through, tossing occasionally, about 7 minutes.
When chicken is cooked through, use a slotted spoon to transfer onto a plate. Set aside.
In the same skillet, add the ghee and melt. Then add the onions, carrots, zucchini, and mushrooms. Cook, stirring occasionally until just cooked and slightly tender (you don't want them too soft, I like a little crunch to mine still), about 4 minutes.
Add chicken back into the skillet with the sesame seeds. Stir and saute for 2 more minutes.
Transfer to a plate and serve with the Magic Mustard Sauce.