Defrosting baked beans in the microwave is not the best option for optimal texture and flavor but it can be done if you are short on time. Run the sealed freezer bag under water to release the frozen beans and sauce from the edges. Decant the beans straight into a microwave-safe dish. You may want to cover the dish with cling film. Microwave the beans for 3 to 5 minutes and stop to stir well, spreading the heat evenly. If not completely defrosted, microwave for 2-minute intervals, stopping between each interval to stir and check that the outer edges are not overheating. Keep in mind that thawing time will largely depend on the size of the portion.