Slice & sauté the onions. Slice one onion into rounds and dice the other.
Cook the onions & meat. Heat the olive oil in the base of the tagine over medium low heat. Add the diced onion, meat, spices, and herbs. Cook, mixing to combine, until the onions begin to caramelize and the meat browns, about 15-20 minutes.
Add the onion rounds & tomato. Arrange the remaining onion (cut into rounds), tomato slices, and cinnamon sticks over top of the meat in a circular pattern.
Top with sauce & saffron. Pour the bloomed saffron & water over the tagine. Spoon some of the sauce from the base of the tagine over the onions and tomatoes. Bring the liquid to a boil.
Cover & cook. Cover the tagine with the lid and lower to cook over medium low heat, or until the onions & tomatoes are fork tender and the beef is fully cooked, about an hour.
Enjoy! Remove the cinnamon sticks. Enjoy your tagine with bread or couscous.