Chicken: Place the chicken pieces between cling film and platen out using a meat mallet or by pressing down the heel of your palm.
Cook the chicken pieces in a pan on the stovetop on a medium to high heat for around 4 minutes each side, until golden brown.
Once chicken is cooked, remove from pan as this will be used to make the mushroom sauce. (Place chicken in oven to keep warm whilst making the sauce)
Lentil Mix: Place the tinned lentils, frozen vege mix, stock and dried herbs into a separate saucepan on low heat for 5 minutes, while you make the mushroom sauce.
Mushroom Sauce: In the same pan that the chicken was in, add the teaspoon of butter, garlic, diced mushrooms and shallots. Toss about for a few minutes until just cooked.
Add the optional lemon juice, followed by chicken stock/broth, cream and pinch of salt. Stir to combine until a sauce is formed.
To thicken the sauce, take a tablespoon of liquid from the pan, and mix it with the cornflour to form a slurry, then add it back into the sauce. Stir to thicken.
To Serve: Place the chicken onto of the lentil mix and drizzle the creamy mushroom sauce over. Garnish with additional chopped shallots.