After washing it, arrange the chicken in a large baking dish. You can use breasts, thighs, or drumsticks--boneless or bone-in. However, if you use bone-in pieces, eating the chicken will be substantially messier, although it will taste just as good! In a large skillet, heat the oil over medium-low heat. Preheat the oven to 375 degrees F (190.5 degrees C).
Add the thinly sliced onions and minced garlic to the oil, and cook them gently, stirring often. Once the onions have wilted, add the peanut butter, coriander, and red pepper flakes to the skillet. Mix everything together well. To intensify the sauce, you can add a dash of salt, a few dashes of black pepper, and an extra 1/2 tsp of red pepper flakes.
Once everything is mixed well, turn off the heat and pour the sauce into the baking dish over the chicken. Place the uncovered dish in the oven and bake the chicken for about 40-45 minutes. If you use chicken that contains bones, cook the dish for about 50 minutes.