Fill large pot of water for pasta.
Trim and discard skin and dark part of swordfish
Cut into 1/2 pieces
toss with flour
heat oil in saute pan
cook swordfish until golden brown on all sides
reduce heat to low and add olive oil to coat pan, add garlic, onion, and capers, 2 Tbsp of parsely, red pepper flakes, and lemon. Cook until onion is translucent.
Add white wine and stir to dislodge any bits. Reduce to half.
Add clam juice OR chicken stock, tomato sauce, salt, black pepper and sugar. Bring to a boil and simmer 8-10 minutes, until slightly thickened.
Add swordfish and any juices amd lemon juice, warm through, about 2 minutes.
Toss with cooked pasta, and serve!