In a medium skillet, sweat onion and garlic in 2 tablespoons of olive oil over medium heat until translucent, about 2 minutes. Let cool and set aside.
Wring the excess milk out of the soaked bread cubes.
Place all ingredients, except flour and garnishes, in a large mixing bowl and combine by hand until fully incorporated. Form into little meatballs (about 1-ounce each).
In a large skillet, heat remaining oil over medium heat. Dredge, or roll the meatballs in flour, and fry in the skillet until golden brown, about 5 minutes. Remove from the pan and place on paper towels to drain the excess fat.
Place on platter and garnish with lemon wedges and torn mint leaves.