As far back as I can remember(high school), this was the very first cooking manga I ever got into, even before I had even heard of Food Wars. And the two have been compared a lot. However, each series has its own themes for the most part.
Apparently, Food Wars is focused on the impact as well as the competition of cooking. Whereas Hell's Kitchen is focused on ideology, the ideas and and for the most part the characters' beliefs during the series. This fits more in line with how the main character Satoru can become anything he chooses given the themes in Hell's Kitchen.
But between the two series, Food Wars was more popular and got an anime because of its art-style. If I had to be honest though, I will never be able to get into Food Wars because of its other issues, but that's a topic for another day.
Hell's Kitchen is also really funny, with all the antics that happen with the cast of characters. There's a lot of creativity that goes into the plot and research in the cooking techniques that does a good job of drawing the readers in. With all of the chapters online, I can happily recommend Hell's Kitchen!