Preheat your oven to 375°F (190°C).

Grease or line a 12-cup muffin tin with muffin liners or non-stick spray. Set it aside.

Grate the zucchinis and potatoes using a box grater or food processor.

Place the grated zucchini and potatoes in a clean kitchen towel or cheesecloth. Twist and squeeze out as much moisture as possible. Removing excess water is crucial to prevent soggy muffins.

In a large mixing bowl, combine the grated zucchini and potatoes.

Add the finely chopped onion, minced garlic, all-purpose flour, grated Parmesan cheese, and baking powder to the mixture.

In a small bowl, lightly beat the eggs, then add them to the large bowl.

Season with salt and pepper to taste.

Stir the vegetable oil into the mixture until everything is well combined. The mixture should hold together but not be overly wet.

Divide the mixture evenly among the 12 muffin cups, filling each about ¾ full. Use a spoon or scoop to ensure even portions.

Place the muffin tin in the preheated oven and bake for 20-25 minutes.

The muffins are done when they turn golden brown on top, and a toothpick inserted into the center comes out clean.

Once baked, remove the muffin tin from the oven and allow the muffins to cool in the pan for a few minutes.

Transfer the muffins to a wire rack to cool completely, or serve them warm if preferred.

Just before serving, top each muffin with a dollop of sour cream and a sprinkle of freshly chopped chives for added flavor and presentation.