I just said what I order and it's called "american breakfast". It's 3x slice of tomato, 2x toast or bread, 2x large bacon, 2x hash brown, 1x egg, 1x sausage and either a cup of tea or cofee. It's 4.20gdp. I also eat lunch there, always for under 5pounds (usually 4.50-4.80). The food is good, portions are big and they have different specialties every day, always under 5pounds. I absolutely love it there and eat there twice a day. Staff is very friendly. It's on Junction Rd in Archway (near Archway station) across the Iceland store. Sorry don't know the exact address.
I also recommend Turkish Cuisine restaraunt in Kentish town (NW5 2AE). I ordered meat mousakka and got three big boxes or mousakka, rice, salad and bread and it was reeeealy good, for 5.90. Their main dishes are 5-8.50.
I also ordered a chicken with rice and pistachio here on Holloway Rd, it cost 9.50 but man I split that into two meals because it was just huge. I don't know what restaraunt was that.
Anyway, that's where I eat. I don't want to bother with cooking and whatnot even though I have time, I would perhaps save some money but it's not expensive either way. I spend no more than 9-10 pounds on food per day, I eat twice, late breakfast at 11-12 and late lunch at 18. Portions are big, every day different food so it's all good. I was definitely expecting to spend more on food in London, so happy to see otherwise.