To prepare a tagliata alla fiorentina recipe, you will first need to prepare the meat. Cut the beef into bite-sized pieces and add it to the pan with the garlic, olive oil, salt, and pepper. Add the chopped onions and cook until the onions are translucent, about 5 minutes. Stir in the tomato paste, then add the ricotta cheese. Cook the mixture over medium-high heat, stirring constantly, until it starts to thicken. Remove it from the heat and set it aside to cool.