Preparation Pat chicken dry and season with salt and pepper. Heat oil and butter in a 12-inch heavy skillet over moderately high heat until foam subsides. Brown chicken on both sides in 2 batches, about 3 minutes per batch. Transfer chicken to a plate and keep warm. Add shallot to skillet and cook, stirring, until tender, about 1 minute. Add wine and deglaze by boiling over high heat, scraping up brown bits, until reduced by half. Stir in cream, tomatoes, tarragon, and bouillon cube, then simmer, stirring, until tomatoes are softened and sauce begins to thicken, 3 to 4 minutes. Season with salt and pepper. Return chicken, with any juices accumulated on plate, to skillet and simmer until cooked through, 4 to 5 minutes. Serve immediately.
Preparation Pat chicken dry and season with salt and pepper. Heat oil and butter in a 12-inch heavy skillet over moderately high heat until foam subsides. Brown chicken on both sides in 2 batches, about 3 minutes per batch. Transfer chicken to a plate and keep warm. Add shallot to skillet and cook, stirring, until tender, about 1 minute. Add wine and deglaze by boiling over high heat, scraping up brown bits, until reduced by half. Stir in cream, tomatoes, tarragon, and bouillon cube, then simmer, stirring, until tomatoes are softened and sauce begins to thicken, 3 to 4 minutes. Season with salt and pepper. Return chicken, with any juices accumulated on plate, to skillet and simmer until cooked through, 4 to 5 minutes. Serve immediately.