Remove seeds and pulp from the pumpkin, cut into bite-sized pieces, and place in a microwave-safe container. Add 1 tbsp of water, cover loosely with plastic wrap, and microwave at 600W for 4–5 minutes until soft. Mix with salt and pepper while hot, mash roughly, and let cool.

Thinly slice the onion vertically and place in a microwave-safe container. Cover loosely with plastic wrap and microwave at 600W for 1 minute. Let cool slightly and squeeze out excess moisture using a paper towel.