In a skillet saute the carrot, onion, and celery.
Then add in the chicken.
Mix the sauce, chicken broth, coconut milk, curry, and harissa.
Pour the sauce into the skillet and turn it onto medium-low, simmering until the chicken is cooked to 165°.
Add in sweet potato if using it and cook until fork tender.
Simmer, don't broil the broth so it doesn't separate. If you find it's not thick enough, mix 1 cup water and 2 tablespoons of cornstarch, mixed (as a slurry) and pour over the simmering sauce, stirring it until the sauce is thickened slightly and creamy.
Add lime juice and chopped cilantro.
Give the sauce a taste and be sure it has enough chicken flavor, curry flavor, spice, and salt. Adjust accordingly.
Serve over rice noodles or rice, or eat by itself for a low carb meal, it’s delicious any way you serve it.