Add your diced bacon to a large pot over medium heat and cook until it turns crisp and golden. Remove the bacon with a slotted spoon and set it aside on a paper towel, but leave the flavorful fat behind in the pot.
Pour the olive oil and butter into the same pot and add your chopped onions. Cook them over medium-low heat for about 10 to 15 minutes, stirring occasionally, until they turn soft and lightly golden.
Stir in the flour, salt, pepper, and turmeric, letting the mixture cook for about 3 minutes so the raw flour taste disappears. This step is what gives the chowder its thick, silky texture later on.
Pour in the chicken stock along with the diced potatoes, then bring everything up to a boil. Reduce the heat and let it simmer uncovered for around 15 minutes, until the potatoes turn fork-tender.
Stir in the corn kernels and let everything cook for a few more minutes. Add the half-and-half and grated cheddar, stirring gently until the cheese melts completely into the broth.
Taste the chowder and adjust the salt and pepper as needed. Ladle it into bowls and top each serving with the reserved crispy bacon for that finishing crunch.