Heat olive oil in a skillet on medium heat.
Add the shallot, garlic clove and tomato paste. Cook the tomato paste until it is brown (a few minutes).
Season the chicken with salt and pepper.
Add the chicken to the skillet and cook until it's browned on every side.
Add the crushed tomatoes.
Cook chicken and tomatoes on a medium heat for about 20 minutes, stirring occasionally. Make sure chicken is cooked thoroughly.
While the chicken is cooking, bring chicken stock to a boil in a saucepan. Add the polenta and let it simmer, stirring often. Add more liquid if needed. You want the polenta to be soft and creamy.
In a small bowl, mix the tahini with lemon juice until it is smooth.
Add the polenta to the skillet with the chicken and drizzle on tahini sauce. Top with fresh parsley leaves.