Cut 300 g chicken fillet into thin slices. Peel and finely chop 25 g fresh ginger root. Finely chop 1 red pepper and mince 1 garlic clove. In a bowl, combine half the chopped ginger, half the garlic, half the chopped pepper, 1 teaspoon cornstarch, and 2 tablespoons soy sauce. Add chicken slices and toss well to coat.
Clean the 400 g Swiss chard. Cut the chard leaves into 1 cm wide strips and the chard stalks into 0.5 cm wide strips. Halve the 150 g cherry tomatoes.
Heat 2 tablespoons oil over medium-high heat in a wok or non-stick pan until hot. Drain excess liquid from the marinated chicken, then add the chicken and marinade to the pan. Stir-fry for 5-6 minutes until the chicken is cooked through (internal temperature 74°C/165°F) with no pink remaining. Transfer the cooked chicken to a plate.
Add 2 tablespoons fresh oil to the same wok or pan over medium-high heat. Add the chard stalks, remaining ginger, remaining garlic, and remaining pepper. Stir-fry for 3 minutes. Add the chard leaves and cherry tomatoes, then stir-fry for 1 minute more.
In a small bowl, whisk together 150 ml vegetable stock, 3 tablespoons soy sauce, and 1 teaspoon cornstarch until smooth. Pour into the wok. Return the cooked chicken to the wok and bring to a simmer over medium-high heat. Cook for 1-2 minutes, stirring occasionally. Taste and season with additional soy sauce if needed, a pinch of sugar, and 1-2 teaspoons lemon juice. Top with 30 g roasted peanuts and serve.