If the baby bella (cremini) mushrooms are not already cleaned, clean the mushrooms very well using a damp cloth or mushroom brush. You may rinse too if the mushrooms have still dirt, but it is not recommended to wash the mushrooms in too much water since they may absorb water. However, it is important to make sure the mushrooms are clean before you cook them, so you may rinse them clean as needed.
Add the cleaned sliced mushrooms to a frying pan.
Add salt and oil, cook in high heat for couple of minutes until water is released from the mushrooms.
Stir the mushrooms, reduce the heat to medium and cook for another 4 to 5 minutes so the water released from the mushrooms is all evaporated.
Add garlic and butter, saute the mushrooms in medium heat for another 5 minutes until the mushrooms are lightly fried and browned. You can flip the mushrooms carefully and cook the other side too for a couple of minutes so they are lightly browned on both sides.
Add lemon juice and soy sauce also to the pan, stir well to coat the mushrooms and sautee for another one more minute.
Serve the sauteed baby bella mushrooms hot for best results!