I do just wing it but I'll share what I do. It may not be the proper way, but it's how we like it.
First boil chicken that is on the bone. Boneless breasts do not work for this. I like thighs best. Give them a decent long boil until the water is yellowed. I add a bay leaf or two in the boil. You don't need a massive amount of water to start, otherwise it would be a bit too loose at sauce stage. But cover all the chicken pieces.
Once they have cooled pick all the chicken off the bone. At this point it should be falling off the bone. Don't discard the liquid.
Put the shredded chicken back into the liquid, add in some mushrooms and frozen green peas. Then I add in cream, and plenty of black pepper. It should come to a not too thick sauce, but if it doesn't I make a slurry with cornflour and use that to thicken a bit. I sometimes just use milk and thicken it up accordingly.
Towards the end I add it a drop of sherry which just gives a nice something to it, but you don't have to do this.
Boil rice. When plating I flatten the rice in the centre a bit and ladle the chicken into the middle.
It's proper comfort food in our house. I boil the chicken in the morning or when I have a gap earlier in the day, as once that is done it is actually very quick to put together.
It's all done in the Dutch oven on the stove top.
I don't put onion in mine as I don't like the texture it gives in the sauce. But you could fry some up separately and add in.
Like I said, no recipe followed so it might not be the correct way according to some recipes.