My husband and I are planning another trip to the UK. We have been to London a few times, but we have always had breakfast included in our hotels. Breakfast is not important to me, since I usually have toast and tea or coffee. But my husband usually wants a standard one, including eggs, or cereal, etc. The two hotels we are looking at, one near Lancaster Gate and one in S. Kensington, both give us the option of room only or room with breakfast.....and the latter one is MUCH higher. So we thought we would opt for room only and find a place for breakfast that would allow him to order whatever he felt like and I could get my tea and toast.......and save a bit of money....or a lot of money!
Even though we know London to some extent, we have never paid any attention to places open for breakfast. Could someone give us their views on where to go in these two neighborhoods, Lancaster Gate and S. Kensington, or for that matter, anywhere in central London, that might be a good bet for breakfast. Thanks.

There is (or was) a little restaurant across the street from the Glouster Road tube stop where my daughter and I ate breakfast one year when we stayed in that area.

Garfunkle's right across from Trafalgar Square

I have never eaten at Garfunkle's, but my family has and they hated it. There is a lovely breakfast at the Church of St. Martin in the Fields, in Trafalgar Square. I know they do a full English breakfast. I don't know whether you can just do toast and milk.

If by South Kensington you mean anywhere on Gloucester Road, or either the Gloucester Road or South Kensington tube stops, there are loads of restaurants and cafes catering to the dozens of hotels on that road. Yu shouldn't have any problem finding something to make you and your husband happy.
Besides the diners which would serve a full English b'fast as well as lighter fare, there are a couple of 'Pauls', the Kensington Marriott for a slightly pricier but very complete full b'fast (buffet, I think) and Cafe Forum at 146 Gloucester Road that many say is a great place for fast, fresh and inexpensive breakfasts and other meals throughout the day.

Other major streets in the S. Kensington area with a bunch of nice places (as well as loads of hotels with hungry guests looking for morning meals) are The Cromwell Road and Old Brompton Road if you happen to be on or near any of those.

Earls Court Road, and definitely the area just outside the tube station of the same name has loads of decent and inexpensive cafes and eating places.

Mathieu is correct. You will trip over places to eat breakfast. We recently stayed half way between the Gloucester Rd and S. Kensington tube stops and had lots of choices. I thought the atmosphere surrounding the S. Ken stop was less frantic and student-jammed than the area around Gloucester Rd station, but either will give you myriad options. I suggest a brief walk around the block from where you chose to stay, and case the area for the coming morning.

Thanks, everyone. I also looked at Tripadvisor and found several suggestions. I don't think we will have any problems.