Chop onions and garlic and dice potatoes.
Over medium heat, heat the olive oil in the bottom of a large stockpot of Dutch oven. Once the oil is hot, add the diced onion and garlic. Sauté until the onion becomes translucent.
Add the chicken stock to the pot with the onion and garlic.
Add in the diced potatoes and thyme. Turn the heat up to medium high, bringing the mixture to a boil.
Once the broth has come to a full boil, reduce the heat to medium.
Allow it to simmer until the potatoes are tender when poked with a fork, about 10-15 minutes.
While it's simmering, cook the hot Italian sausage in a separate skillet, breaking it up into small pieces. Once the sausage is browned and cooked through, remove from heat.
Using a fine mesh sieve or colander, drain the excess grease from the sausage before adding the cooked sausage to the broth.
Add the sweet corn and heavy cream. Stir gently until everything is combined.
Let your chowder simmer for about 5 more minutes.
Remove thyme sprigs and serve hot.