I buy this in my store: https://www.amazon.com/McCormick-Gourmet-Japanese-Spice-Seasoning/dp/B01I6U4O2U (the price on Amazon is outrageous, don't buy it there)

I also use salt, garlic, onion, chili flakes, hot chili sesame oil, and reg. sesame oil. I mix all that into my cubed chicken & let it sit for a few minutes while I get everything else ready.

And I buy the hot (black) Golden Curry blocks.

It's hot, but not too intense. That spice mix has a distinct flavor & heat, but I find if it's too hot then I added too much chili flake.