For the Salsa, put all the ingredients into a food processor and pulse until finely chopped; set aside.
Heat the grill to medium high.
Drizzle some olive oil over the salmon and season it with salt and pepper. Gently rub 2 tablespoons of the Spice Mix into the salmon. Pour some olive oil onto a paper towel and rub the grill with it - this will help to prevent the fish from sticking. Grill the salmon flesh side down for about 12 to 15 minutes.
To serve, spread most of the Salsa onto a platter and place the salmon, skin side down, on top. Garnish with more Salsa, radish slices, cilantro, and a drizzle of olive oil.
Southwest Spice Mix:
Put the ancho chiles, cumin, coriander, cinnamon stick, and paprika into a small dry skillet over medium-high heat, and toast the spices just until they begin to smell, about 1 minute. Empty into a spice mill and grind to a powder.