I really wanted to recreate the flavor of that standard Japanese-style steak sauce, so I thought of this.

This goes really well with beef steak, of course, but it also goes well with sautéed chicken, hamburger, basically any cooked meat!

Be careful not to let the sauce simmer for too long, since you don't want to lose the flavor of the onions.
It's best to cook it just until the bitterness is gone.

If you end up evaporating off too much of the liquid, you can try drizzling on some ponzu when plating. Recipe by Anaboko moufu