Name: Toxic Waste Mac and Cheese
Prep time: 10 min
Cook time: 15 min
Total time: 25 min
Cuisine: American
Ingredients: 1/4 cup unsalted butter; 1/3 cup all-purpose flour; 2 1/2 cups whole milk (or unsweetened cashew milk or Half & Half); 1/2 tsp sea salt; 1/4 tsp ground black pepper; 1/4 tsp paprika; 1 tsp onion powder; 1 tbsp dry mustard powder; 1/16 tsp cayenne pepper (or more, to taste); 8 oz sharp white cheddar cheese, grated (e.g., Vermont sharp white cheddar); 1 package frozen spinach, thawed and drained; Green food coloring (optional, for extra color); 1 lb dry pasta (e.g., medium shells), cooked and drained; 1 head fresh cauliflower, cut and steamed (leave in chunks for visual effect)

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Why You’ll Love This Recipe

I love how playful and unexpected this dish is. It’s rich, cheesy, and creamy—everything I want in a good mac and cheese—but the spinach and cauliflower add a nutritious boost. The green color makes it feel just weird enough to be Halloween-appropriate, and the kids always get a kick out of eating something that looks like it came from a science lab. Best of all, it’s easy to make and comes together in under 30 minutes.

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

1/4 cup unsalted butter
1/3 cup all-purpose flour
2 1/2 cups whole milk (or unsweetened cashew milk or half & half)
1/2 tsp sea salt
1/4 tsp ground black pepper
1/4 tsp paprika
1 tsp onion powder
1 tbsp dry mustard powder
1/16 tsp cayenne pepper (more if desired)
8 oz sharp white cheddar cheese, grated
1 package frozen spinach, thawed and drained
green food coloring
1 lb dry pasta (I like medium shells for a “bumpy” effect)
1 head fresh cauliflower, cut and steamed

Directions

I start by melting the butter in a large pan or Dutch oven over medium-low heat.
I whisk in the flour to make a roux and stir constantly for 1–2 minutes to cook off the raw taste.
Slowly, I pour in the milk while whisking to remove all lumps, then I add the salt, pepper, onion powder, paprika, mustard powder, and cayenne. I keep whisking and cook the mixture until it just starts to simmer—this takes about 6–8 minutes.
Once the sauce is thickened, I remove the pan from the heat and stir in the grated white cheddar until it’s melted and smooth.
I mix in the drained spinach until it’s well incorporated, then add green food coloring until it reaches that toxic green hue I’m going for.
I add the cooked and drained pasta, stirring until every shell is coated in green cheesy goodness.
Last, I gently fold in the steamed cauliflower. I like to leave the pieces in large, creepy-looking chunks so they sit on top and add to the eerie effect.
I serve immediately—bonus points if it’s poured into a cauldron, tin can, or anything that makes it feel like Halloween “waste.”

Servings and timing

Servings: 6
Prep time: 10 minutes
Cook time: 15 minutes
Total time: 25 minutes
Calories per serving: 633 kcal

Variations

When I want to change things up, I use rotini or cavatappi pasta for even more texture. I’ve also blended the spinach into the milk mixture for a smoother consistency. If I want a bit more heat, I add more cayenne or a dash of hot sauce. For a dairy-free version, I’ve used vegan butter, plant-based cheese, and cashew milk—it still turns out great!

Storage/Reheating

I store leftovers in an airtight container in the fridge for up to 3 days. To reheat, I add a splash of milk and warm it gently on the stovetop or in the microwave. I avoid freezing this dish, as the cheese sauce tends to separate after thawing.

FAQs

Can I use a different cheese?

Yes! I like sharp white cheddar because it blends well with the green coloring, but Monterey Jack, mozzarella, or a vegan cheese substitute will also work.

How do I keep the cauliflower from getting mushy?

I steam it just until fork-tender, then fold it in at the end so it doesn’t overcook or break apart.

Is the food coloring necessary?

Technically no, but it gives the dish that Halloween “toxic” look. I use gel food coloring for a deeper green without needing too much.

Can I skip the spinach?

Sure. I like the added nutrition and texture, but if you’re not a fan, the dish is still great without it.

What can I serve this with?

I usually serve it as a main course with Halloween-themed finger foods or a simple green salad. It’s also a great side for spooky burgers or mummy dogs.

Conclusion

Toxic Waste Mac and Cheese is the perfect mix of spooky fun and creamy comfort. I love how easy it is to make and how it always gets a reaction—usually a laugh followed by a second helping. Whether I’m hosting a Halloween party or just making a themed dinner at home, this green, gooey dish brings all the creepy vibes in the most delicious way.