Cook Penne Pasta (500 gram) according to package directions. Once finished, drain and return to pot.
In a separate sauce pot, heat Olive Oil (to taste) over medium heat. Add Carrot (1), Yellow Onion (3), and Fresh Rosemary (2 tablespoon). Cook for about 10 minutes, or until the onions have browned.
Add Ground Lamb (500 gram) and use a wooden spoon to break up the meat. Cook for 6 to 10 minutes, or until the meat has browned.
Add Chicken Stock (3/4 cup). Bring mixture to a boil and then reduce the heat a little. Allow the mixture to simmer for 3 to 4 minutes.
Add Canned Diced Tomatoes (400 gram) and Water (1/2 cup). Stir to combine and season with Salt and Pepper (to taste). Allow sauce to simmer for about 10 minutes or until sauce thickens over low to medium heat.
Stir in Ricotta Cheese (100 gram). Once combined, stir meat sauce through pasta and serve.