Heat a large pot over medium-high heat and add the oil. When hot, add the onion and cook until soft and translucent, stirring often, about 5 minutes. Add the garlic and cook until fragrant, about one minute more. Add the beef, salt, and pepper and cook, stirring to break it up into small pieces. Cook over high heat until cooked through and any liquid released evaporates, about 5-10 minutes more.

While the beef cooks, stir together the stock, gelatin, diced tomatoes, tomato sauce, soy sauce, fish sauce, sriracha, paprika, Italian seasoning, and bay leaf. Set aside.

When beef is cooked, add the reserved tomato sauce mixture and bring to a boil. Reduce heat to a simmer and cook uncovered for 30 minutes.

With about 5 minutes of simmering to go, rinse the kelp ziti with hot water and then add to the simmering sauce. Cook for another 5 minutes.

Remove from heat and stir in cheddar, if using. Let stand 5 minutes to melt, then stir briefly and season to taste with more salt, as needed. Garnish with parsley and serve.