Preheat your oven to 425 degrees with the oven rack in the middle. Line a baking sheet with parchment paper.

Rub the potato with 1 tablespoon olive oil until it is well coated and sprinkle the skin with 1 tablespoon salt. Place the potatoes on the parchment lined baking sheet. Roast the potatoes whole (don't poke any holes in it) until it is soft when you squeeze it with your hand. The baking time will depend on the size of your potato, but usually 45 minutes - 1 hour.

While the baked potatoes are baking, make the broccoli, cheddar and chicken filling. Preheat a large skillet over medium high heat. Add the olive oil, then the chopped chicken breast. Season with salt and pepper. Cook about 4 minutes, flipping half way thru, until starting to turn golden brown. Then add in the broccoli and onion. Season again with salt and pepper. Cook about 8-10 more minutes, until the chicken is cooked thru, and the broccoli and onion are softened. Add in the garlic and cook 30 seconds until fragrant. Remove the pan from heat and set aside.

When you take the baked potatoes out of the oven, drop each one onto the counter or cutting board from 10" up. By dropping it, you loosen the inside of the potato so it is light and fluffy inside when you cut into it.

Cut a slit down the length of the baked potato, pinch the edges together to make the opening bigger, and scoop out the potato from the skin. Transfer the potato to a large bowl. Season with salt and pepper, and add butter and sour cream. Mash with a potato masher. Then fold in the broccoli chicken mixture and 1-1/2 cups of the shredded cheddar cheese. Taste for seasoning, and add more salt/pepper/butter/sour cream/cheese if desired.

Scoop the potato mixture back into the potato skins, then transfer them back to the parchment lined baking sheet. Top the potatoes with the remaining 1/4 cup shredded cheddar cheese, and return to the oven for another 5-10 minutes, until the cheese is melted and bubbling. Serve warm.