Ingredients :

• Three-cheese tortellini — Frozen or fresh — both work. The frozen version is often more consistent and cheaper. What matters is taking them out of the water two minutes before the time indicated on the package: they will finish cooking in the oven, and if you cook them fully now, they’ll end up as mush.
• Pesto — Store-bought jars do the job just fine. Choose one based on olive oil, not sunflower — you can taste the difference. If you have homemade pesto in the freezer, that’s obviously better. Count on about 150g to thoroughly coat all the pasta.
• Chicken sausage — Get fresh chicken sausages, plain or lightly spiced, not smoked. The idea is to slice and brown them quickly in a pan to get some color before they finish in the oven. Fresh rather than pre-cooked — they provide much more juice and texture.
• Mozzarella — Grate it yourself from a fresh ball. Pre-shredded mozzarella is coated in starch to prevent sticking, which interferes with melting — you get a grainy texture instead of a smooth, stretchy melt. Two minutes of grating really changes the result.