In a large saucepan over medium heat, heat about 4 inches of oil until thermometer registers 360°F.
In a large bowl, blend biscuit mix, butter, egg yolks, beer and black pepper to make a smooth batter. Set aside.
In a medium bowl, whisk egg whites until slightly froth. Fold into the biscuit mix. Let stand for about 10 minutes.
Dip vegetable pieces, one at a time, into the batter. Place in hot oil, 4 at a time, and deep fry, turning once, until golden brown, 15 seconds per side. Place on paper towels to absorb excess oil. Transfer to an ovenproof platter and keep warm in preheated oven. Make sure oil is the correct temperature before adding each batch. Serve with a light sprinkling of sea salt. Serves 8.
TIPS: Cut the vegetable pieces the same size so they will fry evenly.
VARIATION: For spicy vegetables, add 1 teaspoons cayenne pepper to batter prior to frying.