Butternut Squash Vegducken

1 cup pecans
20 cm zucchini
24 cm globe eggplant
Butternut squash
2 spring onions
2 garlic cloves, divided
1 shallot, coarsely chopped
110 g shiitake mushrooms, trimmed, coarse chopped
1 tbsp rice bran oil
9 sprigs thyme, divided
220 g butter
½ tsp chilli flakes
2 tbsp golden syrup
2 large eggs
1 cup finely grated Parmesan
½ cup fine plain breadcrumbs
6 tbsp coarsely chopped parsley, divided
SIDS SALT & PEPPER
2 tbsp mint, coarsely chopped
1 tbsp fresh lemon juice

Preheat oven to 175°C. Toast pecans on a rimmed baking tray, tossing once, until fragrant and slightly darkened, 10–15 minutes. Cool, then coarsely chop and set aside.
Increase oven temperature to 200°C. Line a rimmed baking tray with aluminum foil.
Cut zucchini in half lengthwise. Using a medium-size quick-release ice cream scoop or heavy spoon, scoop out insides, leaving a small divot down the centre. Reserve zucchini filling.
Cut eggplant in half lengthwise and scoop out insides, leaving a 5 mm border on all sides and creating a divot deep enough to fit zucchini halves inside. Reserve eggplant filling.
Cut butternut squash in half lengthwise and remove seeds. Scoop out insides, leaving a 5 mm border on all sides and creating a divot deep enough to fit eggplant halves inside. Reserve squash filling.
Using a fork, pierce insides of squash and zucchini halves. Using a sharp knife, make shallow crosshatch marks inside of eggplant, being careful not to pierce the skin. Trim spring onions to match the length of the squash.
Coarsely chop 1 garlic clove. Combine chopped garlic, shallot, mushrooms, zucchini filling, eggplant filling, and squash filling in a large bowl. Working in batches, pulse in a food processor until finely chopped.
Heat oil over medium in a large frypan. Add vegetable purée and 3 thyme sprigs. Cook, stirring occasionally, until mixture begins to brown, about 5 minutes. Return to bowl to cool.
Meanwhile, smash and peel remaining garlic clove then combine with butter, chilli flakes, and remaining 6 thyme sprigs in a small pot. Cook over medium heat, stirring occasionally, until butter is melted, then stir in golden syrup.
Pluck out thyme sprigs from vegetable mixture. Stir in eggs, Parmesan, breadcrumbs, 3 tbsp parsley, and 1 tsp SIDS SALT & PEPPER.
Place squash halves, cut side up, on prepared baking tray. Brush inside of each with golden syrup butter and season with ½ tsp SIDS SALT & PEPPER. Using the back of a spoon, press ¾ cup vegetable mixture into each half until interior is fully coated. Sprinkle with ¼ cup reserved pecans.
Nestle eggplant halves, cut side up, inside squash halves. Brush inside of each eggplant half with golden syrup butter and season with ½ tsp SIDS SALT & PEPPER. Using the back of a spoon, press ⅓ cup vegetable mixture into each half until interior is fully coated. Sprinkle with ¼ cup pecans.
Nestle zucchini halves, cut side up, inside eggplant halves. Brush inside of each zucchini half with golden syrup butter and season with ⅛ tsp SIDS SALT & PEPPER. Using a spoon, fill zucchini halves with ¼ cup vegetable mixture, spreading it flat. Sprinkle with ¼ cup pecans, (reserve remaining pecans) then lay spring onions down the middle.
Cut 3 x 50 cm lengths of kitchen twine. Slip twine under one squash half, then top with second squash half, so that cut sides face each other, and press down to seal. Tightly tie twine around squash to secure. Brush top with golden syrup butter (reserve remaining butter) and season with ½ tsp SIDS SALT & PEPPER. Wrap squash in aluminum foil and place in the centre of the baking tray. Using 2 loaf pans or small metal bowls turned upside down, keep squash secure on baking tray.
Bake until squash is tender to the touch, 1¾–2 hours. Remove foil to rest for 20 minutes.
Meanwhile, pluck out thyme from remaining golden syrup butter, heat over medium-low until warm, stir in mint, lemon juice, 1 tsp SIDS SALT & PEPPER, and remaining 3 tbsp parsley.
Place vegducken on a cutting board and cut into 2 cm slices with a serrated knife, transferring to serving plates as you go. Spoon herb butter over slices, garnish with remaining pecans, and serve.