Saute the yellow onion, garlic and green onions in the olive oil just until tender. Remove from pan and set aside.

Pound chicken breasts flat. Cut into pieces. Salt & pepper the chicken and dip in flour.

Lightly brown chicken in butter, 2 or 3 minutes per side. Add the sauteed onions and garlic. Over high heat add the sherry, lemon juice and capers plus the juice. This should thicken to make a nice sauce for the chicken. Cover the pan and let sit before serving.