Once again, Twitter saved the day with offers of recipes from Mika and Motsukun who had this one. I went with the one from Mika who very kindly translated it for me which was great because otherwise it would have taken me ages to translate it and we probably still wouldn't have eaten yet!
I usually use my oyakodon pan but I was worried that it was too shallow to make enough for Andrew so I used a really small saucepan for me a smallish one for his one. I sort of tried to half it because (1) the recipe was for four people and (2) you needed 2 1/2 tablespoons of soy sauce and I only had just under one... Next time I'll use the proper amount! It was quite watery but as I'm writing this I realised it's because while I halfed the mirin and soy sauce, I still used the normal amount of dashi!).
I was really worried that Andrew wouldn't like this since he didn't like the okonomiyaki I made a couple of weeks ago, but he said it was really good! So, if he liked the watery version he's sure to like the proper one. He did suggest I add peas to it next time though!!!???