Pour in 400 ml broth, cover with a lid, and simmer over medium heat for 50 minutes.
While the beef cooks, place 200 g prunes, 1 teaspoon sugar, and 2 cinnamon sticks in a separate saucepan. Bring to a boil over medium heat, then simmer for 15 minutes. Remove from heat and set aside.
Place 150 g peeled almonds in a dry pan over medium heat. Toast for 3-5 minutes, stirring occasionally, until lightly browned. Set aside.
Cut 3 tomatoes into pieces.
After 50 minutes, remove the lid from the beef pot. Add the tomato pieces and 0.5 teaspoon ground cinnamon. Simmer uncovered over medium heat for 30 minutes, adding more broth if the sauce looks too thick.
Add roughly 3/4 of the cooked prunes to the beef sauce. Simmer over low heat for 5 minutes.
Transfer the beef to a serving dish. Garnish with the remaining prunes and toasted almonds. Serve with potatoes, couscous, spaetzle, or flatbread.