Combine chopped pecans and mint. Spread pecan mixture on a plate or cutting board, and gently roll cheese to coat evenly. Place peaches, lemon juice, and cider vinegar in blender and puree until smooth. Add 1/8 tsp. salt and a pinch of pepper. Add canola oil, and then puree until smooth and thickened. Remove from blender, stir in onion, and adjust seasoning with salt and pepper. Cover and refrigerate if not using right away. In large bowl, add spinach and add enough dressing to coat all of the leaves evenly. Divide dressed spinach on four chilled plates and garnish with blueberries and watermelon. Slice goat cheese into eight equal pieces using tautly held, unflavored dental floss or a knife. Add two slices of goat cheese on top of each salad. Serve immediately. Makes 4 servings.