Trim chicken as necessary and season on both sides (see Note). Melt olive oil and butter in a large skillet over medium-high heat, then add chicken and brown for about four minutes per side. Use tongs to make it easier to flip the chicken, and watch out for spattering.
Flip chicken again, reduce heat under the skillet to medium, and cover the pan. Cook chicken for another 20 minutes covered over medium heat, or until cooked through to an internal temperature of 165 degrees. Time may vary, depending on the size of your drumsticks.
While the chicken is cooking, cut corn off the cob, trim and cut up the zucchini, dice your onion, mince garlic, and halve the tomatoes.
When the chicken is cooked through, remove it to a separate plate and add the onion right into the same pan. Saute onion over medium heat for two minutes, scraping up the browned bits on the bottom of the pan, then stir in the garlic and add the zucchini. Cook for another five minutes over medium heat, stirring occasionally.
Add the corn and cook for another five minutes, continuing to stir occasionally. Add the grape tomatoes, season the veggies with sea salt, pepper, basil, and oregano, and saute for another five minutes.
Once veggies are done, serve skillet chicken drumsticks with the corn/zucchini/tomato medley as a complete dinner.
I find it easier to season the chicken on one side with half of the seasonings, then add to the hot pan seasoned-side down before seasoning the other side.
Skillet Chicken Drumsticks with Corn, Zucchini, and Tomatoes from Mashup Mom: https://www.mashupmom.com/skillet-chicken-drumsticks-with-corn-zucchini-and-tomatoes/