### Large-Scale One-Pan Tomato and Spinach Pasta

This scaled-up version of the one-pan pasta is perfect for feeding a crowd, combining the simplicity and nutritional value of the original recipe with the quantities adjusted for a serving size of 15-20 people. It's an ideal dish for large gatherings, offering a delicious and healthy meal with minimal fuss and maximum flavor.

#### Ingredients:

- 2.5 lbs (about 1.13 kg) spaghetti or any pasta of choice
- 4 cans (14.5 oz or about 410g each) diced tomatoes, undrained
- 10 cups fresh spinach, roughly chopped
- 5 large onions, thinly sliced
- 16 cloves garlic, minced
- 1/2 cup olive oil
- 10 cups water or vegetable broth
- 2 tablespoons dried oregano or Italian seasoning
- Salt and pepper to taste
- Grated Parmesan cheese (optional, for serving)
- Red pepper flakes (optional, for a spicy kick)

#### Instructions:

1. **Combine Ingredients**: In a very large cast iron skillet or several pans (you may need to cook in batches if a single pan isn't large enough), combine the uncooked pasta, diced tomatoes with their juice, sliced onions, minced garlic, chopped spinach, olive oil, water or vegetable broth, and dried oregano. Generously season with salt and pepper.

2. **Cook**: Place the skillet(s) over medium-high heat and bring the mixture to a boil. Once boiling, reduce the heat to maintain a simmer. Stir well to prevent the pasta from sticking.

3. **Simmer**: Continue to cook, stirring occasionally, for about 10-15 minutes, or until the pasta is al dente and most of the liquid has been absorbed. Add more water or broth as needed if the pasta isn't fully cooked and the liquid has mostly evaporated.

4. **Final Touches**: Once the pasta is cooked and the sauce has thickened, remove from the heat. Adjust the seasoning with additional salt and pepper to taste. If desired, sprinkle over some grated Parmesan cheese and red pepper flakes for extra flavor.

5. **Serve**: Serve hot directly from the skillet(s). This nutritious and flavorful meal is easy to prepare, even in large quantities, and is sure to be a hit at any large gathering.

#### Tips:

- To ensure even cooking, especially when preparing such a large quantity, consider cooking in multiple batches or using several skillets if a single large one is not available.
- This recipe is very adaptable; feel free to add other vegetables like bell peppers or zucchini for added nutrition and flavor.
- For a protein boost, consider adding canned beans (such as chickpeas or white beans) along with the tomatoes.
- Opting for vegetable broth over water can significantly enhance the dish's flavor.

This large-scale one-pan tomato and spinach pasta is a testament to the fact that cooking for a crowd doesn't have to be complicated or expensive. With straightforward ingredients and an easy-to-follow method, you can create a wholesome, delicious meal that everyone will love.