Step 1: Prepare and Bake the Potatoes

1. Preheat the Oven: Preheat your oven to 400°F (200°C).
2. Prepare the Potatoes: Wash and scrub the potatoes thoroughly. Pat them dry with a clean towel. Poke each potato several times with a fork to allow steam to escape while baking.
3. Season the Skins: Rub the potatoes with olive oil, then sprinkle with kosher salt and black pepper. This will help create crispy, flavorful skins.
4. Bake: Place the potatoes directly on the oven rack or on a baking sheet. Bake for 50-60 minutes, or until the potatoes are tender and a fork easily pierces through the center.

Step 2: Make the Broccoli Cheese Sauce

1. Steam the Broccoli: Steam the broccoli florets until tender, about 5-7 minutes. Chop into smaller pieces and set aside.
2. Create the Roux: In a medium saucepan, melt the butter over medium heat. Whisk in the flour and cook for 1-2 minutes, stirring constantly, until lightly golden.
3. Add the Milk: Gradually whisk in the milk, ensuring there are no lumps. Cook for 3-4 minutes, or until the mixture thickens slightly.
4. Incorporate the Cheese: Reduce the heat to low and stir in the cheddar and Monterey Jack cheeses until fully melted and smooth. Add the garlic powder, onion powder, and a pinch of salt and pepper.
5. Mix in the Broccoli: Stir the chopped broccoli into the cheese sauce, ensuring even distribution. Taste and adjust seasoning as needed.

Step 3: Assemble the Dish

1. Cut the Potatoes: Once baked, remove the potatoes from the oven and let them cool slightly. Slice each potato lengthwise, being careful not to cut all the way through. Gently fluff the interior with a fork to create space for the sauce.
2. Add the Sauce: Generously spoon the broccoli cheese sauce over the open potatoes, ensuring it drips down into the fluffy interior.
3. Garnish: Top with optional garnishes like crumbled bacon, green onions, or extra shredded cheese for added flavor and presentation.