How do you save on breakfast when staying at hotels?

Beside hotels offering free complimentary breakfast, how can one save money on meals when staying in hotel rooms? I have some food allergies, so I can’t do the hotel breakfast, and hostels/Airbnbs aren’t really an option for me either. Sometimes I can get a room with a kitchenette, but I’m looking for more ways to eat without breaking the bank, especially for breakfast.

I’ve heard of using the coffee pot to make instant noodles, but is that the only trick people use? Or are there other hacks for making meals in a hotel room? I can’t always bring enough food for the whole trip, which of course is the ideal scenario, so would love to hear any ideas, thanks!

Edit: Lots of cool tips in here, thanks a lot all! I'm sure it will help many others as well.
Allergies infos - I didn’t mention my full list of dietary restrictions/allergies because it’s a bit long and complicated, and it really depends on how my health is doing at the time. That’s why I was hoping to find some tips for making things run a bit smoother—not necessarily specific recipes, but more like general hacks.