In a bowl whisk together : olive oil, lemon juice, garlic, thyme, salt and pepper. Add the pieces of chicken and toss to coat well. Let marinade for 15 minutes. (You can prepare the pieces of chicken until that step and cover with plastic wrap. They’ll be good until 24 hours in the fridge).
Prepare barbecue to medium-high heat. Remove the chicken from the marinade and put them on 8 metal skewers (or wood skewers but soaked in water), alternate with the pieces of green bell pepper. Put the skewers on a greased grill and cook 12 to 16 minutes or until the chicken is golden and is not pink inside. Turn the chicken skewers occasionnaly.