01 -
Separate the onions into rings. Nest a smaller ring inside a larger one, leaving a gap. Fit mozzarella strips into the gap between rings and secure with toothpicks.
02 -
In a bowl, mix 1 cup flour, baking powder, and salt until evenly blended. Dredge the assembled onion rings in the dry mixture, coating thoroughly, and set aside on a wire rack.
03 -
In a separate bowl, whisk milk and egg until smooth. Pour into the remaining flour mixture and stir until a batter forms.
04 -
Dip each flour-dusted onion ring into the batter, allowing excess to drip off. Coat immediately in Panko breadcrumbs, pressing lightly to adhere. Place back on the rack to set.
05 -
Heat oil in a deep pot to 350°F. Fry rings in small batches for 2–3 minutes per side until deep golden. Remove to a paper towel-lined plate to drain.
06 -
Carefully remove toothpicks from each ring. Serve immediately with warm marinara sauce on the side.