But as a short PSA: If you really have high cholesterol, this dish might not be the optimal as the vegan butter and sour cream are high in fat - especially saturated fats. This might bring your cholesterol levels up.
If you really need to keep an eye on your cholesterol levels, try not to overdo it with fats in your diet and minimize saturated fats - which are often found in “solid fats” like coconut or palm oil (or any fat derived from an animal source).
You could adapt the recipe quite easily by using a small amount of olive oil to saute the onions & mushrooms. Or you could even go zero-fat by “water sautéing” your ingredients.
The sour cream can be swapped with a “cashew-soymilk-sauce” quite easily. Still has some fat but more on the healty side. And cashews bring a lot of other health nutrients - in contrast to the sour creams.