Add salt and pepper to flour. Dredge chicken in flour and shake off excess.
In a large 12-inch skillet, melt 2 tbl. butter and add 2 tbl. olive oil. When butter/oil sizzles, add chicken breasts and cook just until light brown (about 3 minutes).
When chicken is browned, turn over and cook another 3 minutes. When browned, remove from pan and place on platter.
Add 2 tbl. butter and 2 tbl. oil to pan and when sizzling, add rest of chicken. Cook chicken as above and remove from pan when browned.
Reduce heat to medium and add lemon juice, stock and capers.
Bring to a boil, scraping up brown bits from the pan for extra flavor.
Whisk in the last 2 tbl. butter to thicken sauce.
Return the chicken to the pan and add the artichoke hearts.When chicken is heated, serve.