Mix all meat filling ingredients. Slice potatoes lengthwise into ¼-inch slices. Sandwich filling between two matching slices, pressing gently.
Whisk eggs, tomato paste and spices. Dip mafroom into egg mixture, then coat completely in cornstarch.
Heat oil in a skillet. Fry 5 to 7 minutes per side until golden. Transfer to a wire rack.
In a wide, shallow pot, sauté onion, celery and carrots in olive oil for 7 minutes. Add spices, tomato paste and water. Bring to a gentle boil.
Arrange mafroom upright, side by side in a single layer. Cover and simmer on low for 30 to 45 minutes until potatoes are tender and meat is fully cooked.
