I made both the patties and the buns with vegetable based ingredients. Both macrobiotics dieters and vegans can enjoy these. Unless you absolutely hate natto, I don't think you'll notice any natto-like smell.
5 minutes before you are ready to cook, take the natto packs out of the freezer and open the lids (it's easier to chop if they're frozen, but this isn't essential).
Finely chop the onion.
The natto will still be half frozen, but it's easier to chop. Chop up roughly.
Put the natto, onion, flour, soy milk and pepper in a bowl, and mix well with a spoon.
It should look like this. Not too hard and not too soft.
Heat oil in a frying pan over a high heat, divide the natto mixture into 6 portions, and cook three in the frying pan.
When the natto patties are browned on one side, flip them over right away. Press down on them lightly to flatten them out a bit. Keep pan frying over low-medium heat until cooked through. (Unlike meat, these cook through almost immediately.)
Remove from the pan, and place on a plate to cool. Pan fry the other 3 patties in the same way. You can enjoy these as-is like hamburger steaks if you want.
Sandwich the patties in hamburger buns with pickles, onion, ketchup, soy mayonnaise, etc.
Story Behind this Recipe
My husband made deep-fried fritters from natto, and then used the fritters to make burgers! But I figured you could make the burgers without having to deep-fry the natto, so I tried it out. This has been our family favorite for more than 5 years.
I made the buns using my cinnamon roll dough recipe, divided into 6 portions. The dough rips easily due to the balance of flour and soy milk, so knead with care.