Season breasts liberally with salt and pepper. Heat butter and oil in a large saucepan over medium heat. Add onions pheasant and lightly brown evenly on both sides. Add wine and garlic to pan. Increase heat to medium-high. Remove pheasant breasts and keep warm, but do not overcook! Reduce liquid to about 1 tablespoon. Stir in lemon juice and cream. Bring to a boil and cook for 2 – 3 minutes. Stir in blue cheese until melted. Return pheasant to pan and heat for 1 – 2 minutes. To serve, arrange pheasant breasts on plates, spoon sauce over and top with tomato.