for the roux
3 Tbs butter
1/4 C flour
2 Tbs garam masala (or curry powder)
1/2 tsp cayenne pepper (add less if you want it mild or more if you want it spicy)
fresh ground black pepper
1 Tbs ketchup
1 Tbs tonkatsu sauce (or worcestershire sauce)

for the curry
2 tsp oil
1 large onion sliced thin
2 lbs chicken thighs cleaned and cut into chunks (you could also use beef, shrimp, or tofu)
2 carrots cut into chunks
4 C water
2 large yukon gold potatoes cut into large chunks
1 small apple peeled cored and pureed (I use a microplane)
2 tsp kosher salt (use less if you use regular salt)
1 tsp garam masala
1/2 C peas