Recipe: Alternative sauce for tofu hamburgs. How about some demi glace?

I already have posted a wonderful recipe for tofu patties made with ground meat of your choice (I pick turkey) or one using teriyaki sauce and chicken ground meat, but this time I'll introduce a easy demi glace sauce which goes so well with those patties. Keep in mind that you can completely disregard the ground meat and make tofu hamburgs just with tofu! You can use chicken, turkey, pork, beef ground meat. Possibilities are endless.

Now for the sauce, simply mix the ingredients and heat up in a pan until it starts bubbling. Then it's ready to serve! 

Ingredients
(Makes about 3-4 servings)
Approximately 60kcal per serving

• 4 tbsp ketchup
• 3 tbsp katsu sauce (if you don't have this, you can try with Worcestershire sauce or steak sauce)
• 1/2 tbsp mirin
• 2 tbsp Japanese sake