Japanese Chicken Curry - cooking recipe

Ingredients

2 tablespoons canola oil
550 g boneless skinless chicken thighs, trimmed and chopped into large chunks
2 large onions, thinly sliced (approx. 1 lb)
1/2 tablespoon grated garlic (~2 large cloves)
1/2 tablespoon grated ginger
2 1/2 tablespoons japanese curry powder (I used http -- or /www.food.com or recipe or japanese-curry-powder-532257)
3 cups low sodium chicken broth
2 large carrots, cut into chunks
2 large red potatoes, cut into large chunks (no need to peel)
1 medium japanese sweet potato, peeled and cut into chunks
1 small Asian pear, peeled cored and grated (or apple)
1 tablespoon tomato paste
1 tablespoon cocoa powder
1 tablespoon kosher salt
Chunou Sauce
2 tablespoons all-natural ketchup
2 teaspoons Worcestershire sauce
Roux
1 tablespoon butter
1 tablespoon rice flour

Preparation

Heat the oil in a large Dutch oven over medium-high heat.
Add the chicken in a single layer (work in batches if needed) and let the chicken brown undisturbed (about 5 minutes).
Turn chicken and brown the other side. Remove to a bowl using a slotted spoon and set aside.
Turn down the heat to medium-low and add the onions, stirring for 1-2 minutes to coat with the oil.
Cook, stirring occasionally, until the onions are completely caramelized and almost a paste - roughly 30 minutes.
Raise the heat to medium high and add the garlic, ginger, and curry powder. Saute 1-2 minutes, until very fragrant.
Return the chicken to the pot and add the stock, vegetables, pear, Chunou sauce, tomato paste, cocoa powder, and salt.
Bring to a boil over high heat, then reduce to a simmer, cover and simmer for 35 minutes.
Make a roux by melting the butter in a saucepan and adding the flour. Cook, stirring with a spatula, until the roux is a light brown color. Stir into the curry.
Adjust salt to taste.
Serve with hot rice on the side.