Cut the boneless, skinless chicken thighs into 1- 1 1/2 inch pieces. Sprinkle the coriander, cumin and salt over the chicken, then stir in the yogurt until all the pieces are evenly coated. Cover lightly and let sit for 10 minutes before proceeding.

Melt 1 tablespoon the butter in a large saute pan over medium heat. Raise the heat to medium high and quickly brown about 1/4 of the chicken. Transfer browned chicken to the slow cooker as it is finished, using 1 tablespoon of butter per batch, and repeat until the chicken is all in the slow-cooker. Throw the pierced jalapeno in on top of the chicken.

Prepare the sauce. Return the pan to the heat and melt the butter over medium high heat. Add the onions, garlic, and kosher salt, then stir. Cook, stirring frequently, until the onions begin to lightly brown around the edges.

Stir in the garam masala and ginger and cook until fragrant (about 1 minute) before raising the heat to high and adding the crushed tomatoes and raw sugar. Stir well, scraping the caramelized bits from the bottom of the pan, and bring to a boil. Pour over the chicken in the slow-cooker.

Cover and cook on LOW for 5 hours, or until the chicken is very tender.

Use a fork or whisk to stir the cornstarch or cleargel into the heavy cream until smooth. Pour into the slow-cooker and stir gently until the colour is even. Replace the lid and let cook for 10 minutes or until bubbly around the edges.

Serve over hot rice and peas, topped with a generous amount of chopped cilantro.