Adjust oven rack to middle position and preheat oven to 350°F. Spray a 13x9-inch baking dish with nonstick spray.
Bring chicken stock to a boil and add the rice, broccoli, salt, black pepper and sweet curry. Stir once, cover, reduce heat to low and cook 18-20 minutes or until rice and broccoli are tender.
While rice and broccoli cook:
If using rotisserie chicken, cut the chicken into 1/2-inch cubes or shred the chicken meat (your preference).
If using chicken breasts, sprinkle breasts with salt & pepper. Heat a large skillet over medium heat, and add 2 tablespoons oil to the pan and heat until the oil shimmers. Carefully place the breasts in skillet and cook 4-5 minutes per side (depending on the size of the breasts). Turn off heat and transfer breasts to a paper towel-lined plate to rest (the chicken will continue to cook a bit and will finish cooking while in the oven). Tent the chicken with foil and allow to rest a few minutes, then cut into cubes.
Scoop out the skillet drippings and use the same skillet for sautéing the onions & garlic. If necessary, add 1-2 tablespoons oil and 1-2 tablespoons butter.
In the skillet over medium heat, place the diced onions and cook until onions are translucent. Add minced garlic, stir and turn off the heat.
Add the cut-up chicken, sautéed onion/garlic mixture, half-and-half and cheese to the rice mixture. Mix well.
Pour the mixture into the prepared casserole dish. *See Note.
Sprinkle the cracker topping over the broccoli rice mixture.
Bake 20-25 minutes or until top is golden brown and sauce is bubbly.