Had a pretty good lunch today at Dotori, just by Finsbury Park Station.
I ordered a bulgogi bento box. Meal started out with a small salad (iceberg lettuce in an Asian-style goopy dressing), then the bento box arrived, and it consisted of: bulgogi (generous portion of beef, sauteed with onion, pepper, zucchini), two bbq pork skewers, two veggie gyoza, a bean sprout salad, a radish salad, rice, dipping sauce. I was also served miso soup on the side.
It was a very big lunch, and the total price (without beverage) was £7.90, which I thought was a decent deal considering the quantity of food.
Other dishes on neighboring tables looked good too (bibimbap, sauteed squid, various stews), and while I don't think this is necessarily a destination restaurant, it's not bad if you're in the area, or craving Korean in North London.