Preheat the oven the 375°F.
In an oven proof large skillet heat the olive oil over medium-high heat. Add the onion and cook for 3 to 5 minutes or until the onion softens. Add the garlic and cook for another 30 seconds until aromatic.
Add the mushrooms to the skillet and cook for about 5 minutes until they start to brown and cook down. Season with salt, pepper, chicken bouillon and stir. Stir in the rice and cook for 1 minute, until coated.
Pour in the water, milk and bring to a simmer. Turn the heat to low, cover the skillet with a lid and cook for 20 minutes or until most of the liquid has been absorbed by the rice. Taste for seasoning and adjust with salt and pepper as needed.
Add the turkey and peas to the skillet and toss. Remove from heat.
In a medium bowl combine the breadcrumbs with the butter and sprinkle over the top of the rice casserole.
Transfer the casserole to the oven and bake for 20 to 25 minutes until the breadcrumbs turn golden brown.
