Step 1

Melt butter in a large pan/Dutch oven over medium-low heat.

Step 2

Add the flour and whisk to combine. Simmer, stirring constantly for 1 to 2 minutes.

Step 3

Pour in the milk and whisk to combine and remove all lumps.

Step 4

Add the salt, pepper, onion powder, paprika, cayenne, and mustard, stir to combine.

Step 5

Continue cooking until mixture starts to simmer, 6 to 8 minutes.

Step 6

Remove from heat and add the grated cheese. Stir until melted and completely combined.

Step 7

Add the drained spinach, stir to combine. Add a few drops of green food coloring if desired.

Step 8

Add the drained pasta and stir until completely coated.

Step 9

Stir in the steamed cauliflower, and serve immediately. **I left my cauliflower in large chunks and waited until the very end to add them so they would stay whole, and so they would look creepier sitting near the top.