First you brown the chicken, but there's no need to worry about cooking it through since it goes in the oven once the casserole is put together
Then place the chicken in a single layer in an oven proof dish.
Then onions, mushrooms, and garlic are lightly sautéed in olive oil.
And layer the mixture over the chicken.
Next up is to make the gravy. I think the lemon juice is what really made a difference with this gravy. There is an extra brightness to it that is delicious.
The 1/2 and 1/2 probably doesn't hurt either.
After everything is well-blended and simmered together for a bit so there is no floury taste, then the gravy is poured over the mixture in the casserole dish.
The dish is covered with foil, and baked for 45 minutes.
Serve it with pasta, rice, noodles, or mashed potatoes!
