Place ancho chilies in 1 cup boiling water to rehydrate.
When plump, slit chilies and scrape out seeds. Discard seeds.
In a food processor, combine chilies, canola oil, brown sugar, salt and freshly ground pepper. Process until ingredients form a paste.
Spread chili paste over whole salmon fillet. Using your fingers (wearing rubber gloves if you like), massage paste into fish.
Allow salmon to marinate, covered, in the refrigerator overnight.
When ready to enjoy, Preheat oven to 375°F.
Place fish on an ungreased pan. Place in oven and bake for 15 to 18 minutes, or until firm to the touch.
While fish is cooking, make the sauce. Combine basil leaves, garlic, olive oil, Parmesan cheese and 1 teaspoon coarse salt and 1/2 teaspoon pepper, to taste, in the work bowl of a food processor. Puree until smooth.
To serve, mound salad greens in the center of a serving plate. Top with salmon. Generously drizzle with basil sauce.