1.Preheat oven to 200°C/400°F. Line an oven tray with baking paper.
2.Place stock, peppercorns and bay leaf in a medium saucepan over medium heat. Add chicken; if chicken is not covered in stock, add a little water. Bring to the boil; reduce heat to low, simmer, uncovered, for 4 minutes. Cover pan, turn off heat; stand for 30 minutes.
3.Meanwhile, place brussels sprouts on tray, drizzle with half the oil; toss to coat. Turn sprouts cut-side up; season. Roast for 20 minutes or until crisp and golden.
4.Then, to make superfood pesto; process basil, kale, almonds, parmesan, juice and garlic until finely chopped. With motor operating, gradually add oil in a thin, steady stream; process until smooth. Stir in spirulina; season to taste.
5.Place kale and remaining oil in a large bowl; season with sea salt. Using your hands, rub oil and salt into kale until kale softens.
6.Remove chicken from the poaching liquid; shred coarsely.
7.Divide kale between bowls; top with brussels sprouts, chicken, avocado, almonds and pesto.
Pesto can be made up to 4 days ahead. Store, tightly covered, in a small airtight container in the fridge.Note