Wash the squash and pat dry.

Preheat the oven to 350F/180C/gas mark 4. Line a baking sheet with parchment paper or a silicone mat.

Slice each squash in half lengthwise and use a grapefruit spoon to scoop out the seeds.

Brush each cut side with olive oil and sprinkle with black pepper and a little sea salt (omit salt for very low-sodium diets).

Place on baking sheet, cut side down, and roast for 20 minutes or until soft.

Meanwhile, heat about 1 tbsp. olive oil in a nonstick skillet or cast iron pan over medium heat until shimmering.

Sauté the celery and pumpkin seeds for 10 minutes until golden and the seeds begin to pop. Remove from heat.

Once the squash are cool enough to handle, scoop out the roasted flesh into a bowl. Add the remaining ingredients and stir well to combine.

Stuff the mixture back into the squash shells and broil for 3 minutes until the tops are golden brown. Serve at once, topped with additional lemon zest and a drizzle of extra virgin olive oil if desired.