In a large pot or casserole bring water to a boil on high heat adding a generous amount of salt. Add the pasta, stirring occasionally so as not to stick and cook according to suggested time on the box of the pasta less 2 minutes. Reserve ½ cup of cooking water.
Turn the oven on at 200°C, air ventilation, rack in the middle.
Take a small sauté pan, oven proof, and place on high heat. A minute later add the smashed garlic and the thyme. Sauté for 30’’ and then add in the tomatoes. Toss and sauté for 2 minutes and take off the fire. Place in the oven and cook for 15’. Remove from the oven, discard both garlic and thyme sprigs and keep the tomatoes aside.
In the meantime, in a large and deep-frying pan over low heat add the Pesto Genovese sauce and keep warm.
Strain the pasta and return to the saucepan with the pesto sauce. On low heat stir for a minute so as the pasta absorbs the sauce. Add from the reserved water if consistency is on the thick side.
Immediately add half of the cherry tomatoes, loose from their branch, and toss carefully so as not to break them.
Serve in a deep dish, add the Halloumi cheese and the remaining cherry tomatoes on their branch. Finally, drizzle on top the rest of the oil.