In a large skillet or Dutch oven, heat the coconut oil over medium heat. Once hot, add the finely chopped Vidalia onion. Sauté for about 5-7 minutes, or until the onion becomes translucent and fragrant.
Add the minced garlic, turmeric, garam masala, ground ginger, cumin, coriander, salt, and black pepper to the onions. Stir well to combine and let the spices toast for about 1-2 minutes until they are aromatic.
Add the diced chicken breast to the skillet. Cook for about 5-7 minutes, stirring occasionally, until the chicken is no longer pink and is starting to brown.
Reduce the heat to low and pour in the can of coconut milk. Stir well to combine all the ingredients. The creamy coconut milk will create a luscious sauce.
Stir in the cashews and adjust the seasoning with more salt and pepper if necessary. If you like a hint of sweetness, add the brown or white sugar at this point. For a citrusy kick, squeeze in the lime juice.
Let the curry simmer for 10-15 minutes, allowing the flavors to meld. If you prefer a thicker sauce, simmer it uncovered, stirring occasionally.
Taste your curry and adjust the seasonings according to your preference. If you like heat, add a pinch of cayenne pepper or red chile flakes. Once satisfied, remove from heat.
Garnish the curry with freshly minced cilantro before serving. Pair with steamed rice or naan for a complete meal.