Heat rapeseed oil in a pan over medium-high heat. Add chicken and mushroom cubes and fry for 10 minutes, stirring occasionally. Sprinkle with dill and season with salt and pepper.
Divide the chicken mixture between two small casserole dishes.
Top each with cocktail tomato halves.
Sprinkle with basil.
Cover with mozzarella slices.
Bake for 15 minutes until cheese is melted and chicken reaches 74°C (165°F) internally.