Preheat your oven to 400°F (200°C).

Pierce each potato several times with a fork.

Microwave the potatoes on high power for about 8-10 minutes. Rotate the potatoes halfway through the cooking time for even cooking.

While the potatoes are cooking, heat olive oil in a skillet over medium heat. Add chopped red onion and sauté until softened, about 2-3 minutes.

Add sliced mushrooms to the skillet and cook until they release their moisture and start to brown, approximately 5-6 minutes.

Next, add the cherry tomatoes and cook for a further 3-4 minutes.

Stir in baby spinach and soy sauce and cook until wilted, about 1-2 minutes. Remove the skillet from heat.

Once the potatoes are cooked, remove them from the microwave and allow them to cool slightly until they can be handled.

Slice off the top quarter of each potato lengthwise and gently press the potatoes.

Stuff each potato shell with the fillings, packing it in tightly.

Place the stuffed potatoes on a baking sheet lined with parchment paper and bake for an additional 10-15 minutes, or until the cheese is melted and bubbly.

Once baked, remove the stuffed potatoes from the oven and let them cool for a few minutes before serving.

Garnish with chopped parsley, if desired, and serve hot.