It's not the same as cooking pork or chicken adobo. Mushrooms are fatless and you can't make them render fat no matter how long you cook them. You'll only make them shrink if you cook them for too long. You don't add soy sauce either--the mushrooms brown in oil fast and adding soy sauce will make the cooked dish far too dark to look attractive. Does that mean that this is something more complicated that meat adobo? Actually, no. This is easier and simpler.