Place the chicken into a large dish. Pierce 1-inch slits through the chicken skin into the meat (about 1/2-inch deep. Pour in the beer; add the crushed garlic, stock powder and salt; turn the chicken skin side down; cover with foil and refrigerate for 4-6 hours or overnight for a deeper flavour. (Rotate the chicken once while marinading to ensure an even flavour when baking).
When ready to cook; preheat your oven to 210°C | 410°F. Drain the beer marinade (reserving the liquid), and heat a cast iron skillet or oven proof pan (see notes) on medium-high heat. Add 1 tablespoon of oil to the pan; and when it starts to smoke sear chicken, skin side down for about 4 minutes until the skin is golden and crisp, then flip and sear until golden.
Transfer pan to the oven and continue to cook for a further 30 minutes, broiling for the last 5 minutes, until the chicken is completely cooked through.
Gravy:
While the chicken is in the oven, fry the shallots and mushrooms in a separate hot pan with a drizzle of oil. When fragrant; add the reserved marinade and simmer on medium-high heat for 5 minutes. Set aside.
In a smaller saucepan, melt the butter. Lower heat and whisk the flour through until lump free. Add the shallot and mushroom mixture along with the liquid, and stir until combined. Add the (extra) 1/2 cup of lager and cook until thickened, stirring occasionally.
When gravy is thick, stir the cooking cream through along with the sugar. Season with salt to suit your tastes.
To Serve:
Serve with creamy mashed potatoes, rice or steamed vegetables. Pour gravy over the chicken; or to retain crispiness, serve gravy onto the side of your serving plates. Sprinkle with finely chopped thyme or parsley.
Notes
Use a mild lager for the gravy, otherwise the flavour may be too strong. We like Corona, but you can choose a milder lager.
If you don't have an oven proof pan, simply transfer the chicken pieces from the frying pan you're using into an oven proof baking dish, and pour any left over juices from the pan onto the chicken.
Nutrition calculated for one serve (1/4 of recipe).