Pasta with Sardines

Name: Pasta with Sardines
Ingredients: 1 1⁄2 lb. cleaned fresh sardine filets (about 50); Semolina flour, for dredging; 1 cup olive oil; 2 medium fennel bulbs, finely chopped, fronds reserved; 2 medium yellow onions, finely chopped; 3 tbsp. tomato paste; 6 oil-packed anchovy filets, drained and finely chopped; 1 cup tomato sauce; 3 tbsp. dried currants; 3 tbsp. pine nuts; 1 tsp. freshly grated nutmeg; 1⁄4 tsp. saffron; Kosher salt and freshly ground black pepper, to taste; 1 lb. spaghetti