Start by marinading the chicken. Slice chicken up into bite-sized pieces. Then, season the chicken with the 'marinade' seasonings.
Place into a bowl, baggie or container and add in the yogurt. Toss to combine. Place a lid on the container (or seal the bag) and store in the fridge for 30 minutes to allow the chicken to marinade in the sauce.
Once the chicken is done marinading, heat a large pan over medium / high heat. Drizzle with oil or spray with cooking spray.
Add chicken (without rinsing or rubbing off the marinade) and sauté until fully cooked. I move around and flip the chicken every few minutes. Then, set the pumpkin curry chicken aside on a clean plate.
In the same pan, add the butter and allow it to melt. Then, add the diced onions and sauté for 2-3 minutes. Add the minced garlic and cook for another minute.
Combine with the remaining sauce ingredients and bring the heat down to low/medium. Then, stir everything together and allow it to come to a slight simmer.
Once simmering, remove from heat, add the chicken back in, then, toss the pumpkin curry to coat.