My worst was probably the first dinner for company in our very first house.
I wasn't planning anything too ambitious. We were broke (did I say we'd just bought our first house?); we were still arranging the kitchen for optimum use; our friends were not foodies. So the meal was casual: pasta, salad, garlic bread, etc.
I had made the pasta sauce in advance and stashed it in the freezer. Just before the guests arrived, I began to heat it up in the microwave. Pulling the pot out to stir it, I managed to upset it ... spilling thick, boiling-hot tomato sauce over my wrist.
So our friends arrived to find tomato sauce splattered all over the kitchen and me holding my arm under running water in the sink and trying not to scream.
They finished making dinner while my husband cleaned up. I got through the meal with my hand in a large bowl of ice water. After they went home, we went to the emergency room where they took away my ice water, wrapped the arm up painfully and informed me I would probably need a skin graft.
Ultimately, the doctors decided against the graft, but that section of skin is still faintly scarred and somewhat sensitive, two decades later.
My kitchen mishaps rarely mess up the food irretrievably, but I do wind up damaging myself, sometimes permanently. I have sliced the tip of my finger off with a mandolin, burned various unlikely parts of my body (do not bake without clothes on, no matter how hot the weather is) and dropped a 2-pound jar of honey on my instep to devastating effect.