Heat the butter and olive oil in a large pot over medium heat until it's shimmering and smells amazing. Once you see that sizzle, add your chopped onion and cook for about 3 minutes until it gets translucent and soft.
Toss in the minced garlic and cook for exactly 1 minute—this is important because garlic burns fast and tastes bitter if you overdo it. Stir constantly so the garlic coats everything evenly.
Add the diced potatoes and pour in the chicken broth, then bring the whole thing to a boil. Once it's bubbling, reduce heat to medium-low and let it simmer for about 8 minutes until the potatoes start getting tender but aren't completely soft yet.
Now stir in your 2 cups of corn kernels, the smoked turkey strips, thyme, salt, and pepper. Let everything simmer together for another 5 minutes so the flavors meld and the corn gets cooked through.
Pour in the milk and bring the temperature back up to a gentle simmer (not boiling). Stir frequently here because this is when things thicken up, and I always watch it carefully to make sure nothing sticks to the bottom of the pot.
Remove the pot from heat and sprinkle the cheddar cheese on top, then stir it in immediately. Don't crank the heat back up after adding cheese—just let the residual warmth melt it into something beautifully creamy.