1. For spice rub, combine and stir all ingredients.
2. For red pepper coulis, roast peppers in 450-degree oven until the skins are dark. Cool. Remove skins and seeds. Add peppers and remaining ingredients in blender and puree.
3. For avocado puree, combine ingredients in blender and puree.
4. For crème fraiche, combine ingredients. If sauce is too thick, add a little water to achieve desired consistency.
5. Rub one side of tuna filet with the South Western rub and place rubbed side down in hot sauté pan with one tablespoon of oil. Sear both sides and cook to desired temperature. Rare is recommended.
6. Transfer to plate.
7. Garnish with tortilla, sauces and salsa, if desired.
Serves 4