1 Cutting board, 1 Small knife, 1 Large knife, 1 Melon baller, 1 Bowl, 1 Tablespoon, 1 Mini food processor, 1 Wooden spoon, 1 Baking sheet, 1 Parchment paper
1 Trim kohlrabi and set aside the greens. Peel kohlrabi, cut in half crosswise and scoop out all the halves using a melon baller, leaving a 1 cm (approximately 1/2 inch) margin.
2 Cut the scooped kohlrabi flesh into small pieces and put in a bowl. Rinse the scallions, pat dry cut into thin rings. Add to the bowl.
3 Peel garlic and chop finely. Finely chop walnuts with a large knife. Add both to the bowl.
4 Cut feta cheese and the bread into small pieces. Add to the bowl along with the oil and toss to combine.
5 Rinse basil and kohlrabi leaves, shake dry and chop coarsely. Puree with the egg in a mini food processor.
6 Mix the egg mixture with the bread mixture and season with salt and pepper. Season the kohlrabi halves on the inside with salt and pepper and divide filling among halves.
7 Line a baking sheet with parchment paper and place the stuffed kohlrabi halves on top. Bake on middle rack of preheated oven at 180°C (fan 160°C, gas mark 2-3) (approximately 350°F/convection 325°F) until golden brown on top, about 30 minutes. Garnish each with 1 dollop of sour cream and serve.