Prepare breast halves by trimming fat and slicing each in half lengthwise.
Season with salt and pepper.
Pulse tortilla chips in a food processor until coarsely ground; transfer to a shallow dish. Place flour in a second shallow dish, and in a third shallow dish, blend egg and salsa together with a fork.
Dredge both sides of chicken in flour, then dip into egg mixture to coat. Transfer chicken to ground chips and pat them onto both sides; place on a baking sheet or plate.
Heat oil in an overproof saute pan over medium-high. Saute chicken 3 minutes, or until golden brown. Carefully flip chicken, thenplace thepan in the oven to roast for 8-10 minutes, or until cooked through.
While chicken is roasting, puree avocado, milk, and sour cream in a food processor or blender. Add remaining ingredients and pulse until smooth.