Mix together salt, pepper, coriander, mustard powder, celery salt, paprika, turmeric, and cayenne pepper in a small bowl.
Melt butter in a large skillet over medium-high heat. Add diced onion and pasta. Cook and stir until onions soften and pasta turns golden brown, 4 to 6 minutes. Stir in spice blend; cook and stir about 30 seconds. Add rice and stir until rice is coated with butter, about 1 minute.
Pour in chicken broth. Bring to a simmer. Stir; reduce heat to low. Cover with a tight-fitting lid; cook for 17 minutes. Remove from heat; let covered skillet sit for 5 minutes. Remove lid and stir in parsley, fluffing rice and breaking up any clumps.