In a medium bowl, combine the drained sardines, beaten eggs, breadcrumbs, chopped vegetables, and seasonings. Mix until a soft, sticky dough forms.

Divide the mixture into 2 or 3 equal portions and shape into patties about 1 inch thick.

Create a deep well in the center of each patty to hold the egg yolk.

Chill the patties in the refrigerator for 10-15 minutes.

Carefully place one egg yolk into each well of the chilled patties.

Heat about 2 tablespoons of oil in a skillet over medium heat.

Gently place the patties yolk-side up in the skillet, cover, and cook for 6-8 minutes until crispy.

Remove the patties from the skillet and serve immediately while warm.