In a pot, sauté onions with olive oil over medium heat.
Stir in tomato paste and sauté for 1-2 minutes.
If you are using fresh spinach, wash, drain, and chop.
If using frozen spinach, add them into the pot.
Cook them over medium heat stirring occasionally until most of the water evaporates (5 minutes).
Stir in bulgur and add hot water, crushed red pepper, and salt.
Close the lid and cook over low heat for 20-30 minutes, until the bulgur is cooked.
Serve it with yogurt on top or on the side.