My crockpot has the option to have the inside part be placed on the stove first and then inserted into the base to cook- if yours does not you can do this in a pan and transfer to the slow cooker.
So first I place my slow cooker inside pot on the stove on medium heat with the olive oil and onions with a pinch of salt and cook about 5 minutes and then I add the garlic and cook another minute. Then I add in the chicken thighs and season them with salt and pepper and cook about 1 minute per side and then turn off the heat and add the base back into the slow cooker.
Next, I add the sliced mushrooms to the slow cooker along with the chicken broth, wine, basil, parsley and some more salt and pepper and let it cook on low for 3 & 1/2 hours.
The last 30 minutes I add in the orzo and let it cook until soft about 25-30 minutes. Once everything is done after the 4 hours total I add in the sour cream and stir until melted into the sauce and squeeze some lemon over the top and enjoy!