Follow these steps carefully to achieve the perfect Spaghetti Squash Chicken Bowl:

1. Prepare and Cook the Spaghetti Squash:
* Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.
* Carefully cut the spaghetti squash in half lengthwise. This can be tricky, so use a sharp, sturdy knife and be cautious. If it’s too hard, you can pierce it a few times with a fork and microwave it for 3-5 minutes to soften the skin slightly before cutting.
* Scoop out the seeds and stringy pulp from the center of each half using a spoon, much like you would with a pumpkin.
* Drizzle the cut sides of the squash with about 1 tablespoon of olive oil and season generously with salt and pepper.
* Place the squash halves cut-side down on the prepared baking sheet.
* Roast for 35-50 minutes, or until the squash is tender and the skin gives easily when pressed. The exact time will depend on the size of your squash. You should be able to pierce the flesh easily with a fork.
* Once cooked, remove from the oven and let it cool slightly, for about 10-15 minutes, until it’s safe to handle.
* Using a fork, gently scrape the flesh of the squash. It will naturally separate into spaghetti-like strands. Scrape all the strands into a large bowl and set aside.

2. Cook the Chicken:
* While the squash is roasting (or cooling), prepare the chicken. Pat the cubed chicken breasts dry with paper towels. Season them generously with salt, pepper, and about ½ teaspoon of the smoked paprika.
* Heat 1 tablespoon of olive oil in a large, deep skillet or Dutch oven over medium-high heat.
* Once the oil is shimmering, add the seasoned chicken cubes in a single layer. Be careful not to overcrowd the pan; cook in batches if necessary.
* Cook for 5-7 minutes, stirring occasionally, until the chicken is golden brown on all sides and cooked through (internal temperature reaches 165°F or 74°C).
* Remove the cooked chicken from the skillet and set it aside on a clean plate.

3. Sauté the Aromatics and Vegetables:
* To the same skillet (no need to wipe it clean, those browned bits are flavor!), add the chopped yellow onion. Sauté over medium heat for 3-4 minutes, or until softened and translucent.
* Add the minced garlic and cook for another minute until fragrant, stirring constantly to prevent burning.
* Add the sliced red and green bell peppers to the skillet. Cook for 5-7 minutes, stirring occasionally, until they are tender-crisp.

4. Build the Sauce:
* Stir in the tomato paste, the remaining Italian seasoning, the rest of the smoked paprika, and the optional red pepper flakes. Cook for 1-2 minutes, stirring constantly, to toast the spices and deepen the flavor of the tomato paste.
* Pour in the undrained diced tomatoes and the chicken broth. Stir well, scraping up any browned bits from the bottom of the pan (this is called deglazing and adds a lot of flavor).
* Bring the sauce to a gentle simmer. Reduce the heat to medium-low, cover, and let it simmer for 10-15 minutes, allowing the flavors to meld together. Stir occasionally. Taste and adjust seasoning with salt and pepper if needed.

5. Combine and Finish:
* Return the cooked chicken to the skillet with the sauce. Stir to combine and allow the chicken to heat through for a couple of minutes.
* Add the fresh spinach to the skillet. Stir gently until the spinach is wilted into the sauce, which should only take 1-2 minutes.
* Now, you have two options for serving:
* Option A (Mixed): Add the cooked spaghetti squash strands directly to the skillet with the chicken and sauce. Toss everything together gently until the squash is well-coated and heated through.
* Option B (Layered): Divide the spaghetti squash strands among individual serving bowls. Then, ladle the chicken and vegetable sauce mixture generously over the top of the squash.
* Garnish with grated Parmesan cheese and freshly chopped parsley or basil, if desired. Serve immediately and enjoy!