How to Make It
Combine tomato, onion, jalapeño, garlic and salt in a medium bowl; mix well (To make salsa ahead, prepare to this point; cover with plastic wrap and chill, for up to 1 day, until ready to serve.) Stir in cilantro.
Prepare grill. Put ground beef, tomato sauce, bread crumbs and egg whites in a large bowl. Mix with hands or a wooden spoon until well blended. Divide mixture into 4 portions and pat into ovals about 2/3 inch thick.
Grill meat loaves over medium flame, turning once or twice, until nicely charred and cooked through, about 15 minutes.
While meat cooks, slice potatoes 1/4 inch thick; rinse and pat dry. Brush potato slices on both sides with olive oil and grill, turning once, until golden and crisp, about 12 minutes. Sprinkle with salt.
Spoon salsa on loaves; serve with potato slices.