Nowhere else to turn. Is lasagna a thing, or a collective of things?
Seems silly, but temporaly tied to how we use language nowadays.
I have baking (as I type, mind you... ) a glass dish filled with layers of flat noodles, cheeses, spinach, and a meat/veggie sauce.
Am I baking lasagna?
Am I baking a lasagna?
It's a dish, which is one word describing a specific arrangement of ingredients. Happens all the time in language.
You could say I'm running as fast as possible, or say I'm sprinting. One is quicker to say.
You have autism
It's "a lasagna" OP, as the lasagna is considered a complete thing which is then separated for serving.
Same with 'a casserole' or 'a cake'.
But that's really being technical, it's not that concerning.