Preheat the oven to 400°F.

In a small bowl, combine all seasoning mix ingredients and set aside.

Drain the canned tomatoes, reserving the liquid. Coarsely chop the tomatoes.

Pulse the seitan in a food processor about 12 times until shredded.

In a Dutch oven, combine the reserved tomato liquid and vegetable broth.

Bring to a boil over medium-high heat, add the brown rice and 1/4 teaspoon salt, then cover and simmer for 20 minutes.

While the rice cooks, heat the olive oil in a skillet over medium-high heat.

Add the chopped onion and cook until slightly softened.

Add the garlic, red bell pepper, celery, and seasoning mix.

Stir well, then add the chopped tomatoes and shredded seitan.

Cook for about 3 minutes, stirring to combine.

Transfer the vegetable mixture into the Dutch oven with the rice.

Stir well, cover, and place in the oven.

Bake for 30 to 45 minutes, until the liquid is absorbed and the rice is tender.

Remove from the oven and let stand, covered, for 5 minutes.

Stir gently and serve garnished with fresh parsley.