1. Start cooking bulgur in a large pot according to package directions, and cook shells in a large pot according to package directions. Drain shells when done. Blend tomatoes in a food processor until smooth.
2. Heat oil in a medium pan over medium heat. After hot, add onions and garlic and saute until tender, approximately 7 minutes. Add tomatoes and cook until slightly thickened, approximately 20 minutes. Preheat oven to 350 degrees F.
3. Steam spinach in separate pan until wilted, and squeeze out water when done. Add spinach to bulgur. Add salt, pepper, and egg replacer. Stir until combined. Remove from heat and add nutritional yeast, vegan parmesan, and ricotta, if using. Stir.
4. Coat bottom of 9x13″ glass pan with tomato/onion mixture until just slightly coated (approximately 1 cup). Spoon bulgar/spinach mixture into shells and arrange in pan. Cover with remaining tomato/onion mixture.
5. Cover with aluminum foil and bake until bubbling, approximately 40 minutes. Sprinkle with vegan parmesan before serving, if desired.
Source of recipe: Adapted from recipe in Whole Living, March 2011, pg. 93.