Start by heating a pot of salted water for the pasta. Be sure to check out my pasta cooking tips. Add the pasta and cook until al dente when the water is at a boil.
Get all your ingredients ready. This is called mise en place. Start by finely chopping the shallot or onion, mincing the garlic, slicing the sausage and slicing the kalamata olives. Cut the fresh mozzarella into small pieces.
Heat a small saucepan, and when hot, add the olive oil. When the olive oil is hot but not smoking, add the shallot and cook on medium-high heat for a few minutes.
Add the garlic, being careful not to let it burn. I will shake the pan or use a wooden spoon to prevent this. I let that cook for about a minute and then added the cooked sausage and kalamata olives.
I let this cook for a minute or two and then add the beef or brown stock. Let this reduce by about half. I also like to add a little of the water the pasta is cooking in because it has some starch in it from the pasta. It doesn't take much--maybe ¼ to ½ cup.
This starch, combined with the cheese and olive oil, will help form an emulsion to thicken the sauce and help make sure that the sauce sticks to the pasta. Taste the sauce, and season with salt and pepper.
When the pasta is perfectly cooked "to the tooth," drain it and add it to a serving bowl.
Add the cut-up mozzarella cheese and then the sauce. The heat from the pasta and the sauce should melt the fresh mozzarella.
Serve immediately in warmed bowls.