Pour the oil into a large pot set over medium-high heat.
Add the onions, garlic, bell peppers, potatoes, carrots, bay leaves, dried oregano, and a pinch of salt and pepper. Cook, stirring often, until onions are soft and translucent, about five minutes.
Stuff the lemon quarters into the cavity of the chicken. If there is room, move the vegetables to the side, and saute the whole chicken on all sides until lightly browned. Otherwise, simply add the chicken to the pot.
Pour in enough of the beer to mostly cover the chicken. It only took me 4 ½ cups, but could take up to 6 cups if you have a larger pot. Stir well, and once the liquid comes to a simmer, cover the pot and turn heat to medium-low.
Cook until chicken is done and potatoes are tender, about 45 minutes.
Remove chicken and let cool for a few minutes. Then carve into eight pieces, and serve in a wide bowl with the vegetables and broth.