Prepare the Gnocchi

Preheat oven to 400°F (200°C). Pierce potatoes several times with a fork and bake directly on the oven rack for 50-60 minutes until completely tender when pierced. Baking rather than boiling keeps potatoes dry for lighter gnocchi.

Cut potatoes in half and scoop flesh immediately into a potato ricer or food mill set over a large bowl. Rice all potato while still steaming—this releases moisture. Spread riced potato on a sheet pan and let cool for 5 minutes.

Gather cooled potato into a mound on a clean work surface. Make a well in the center and add egg yolk, salt, and white pepper. Sprinkle flour over the top. Using a bench scraper or your hands, gently fold and press the mixture together until a soft dough forms. Work quickly and handle minimally—overworking develops gluten and creates dense, gummy gnocchi. The dough should be slightly tacky but not sticky.

Divide dough into 4 portions. Roll each portion into a ¾-inch (2cm) rope on a lightly floured surface. Cut ropes into 1-inch (2.5cm) pillows. For traditional ridges, roll each piece gently down the tines of a fork. Transfer shaped gnocchi to a floured sheet pan in a single layer.

Prepare the Bengali Tomato Sauce

Heat mustard oil in a large deep skillet or kadhai over medium-high heat. When the oil begins to smoke lightly (this tempers mustard oil's raw pungency), reduce heat to medium. Add panch phoron and additional nigella seeds. Let them crackle and pop for 20-30 seconds until fragrant.

Add ginger and garlic, stirring constantly for 1 minute until golden and aromatic. Add the slit green chilies and stir for 30 seconds.

Add chopped tomatoes, turmeric, cumin powder, coriander powder, and gochugaru. Stir to combine and cook over medium heat for 10-12 minutes, stirring occasionally, until tomatoes break down completely and oil begins to separate at the edges of the pan. This oil splitting is the hallmark of a properly cooked Bengali base.

Add sugar to balance the tomato's acidity (a signature Bengali technique), lemon juice for tanginess, salt to taste, and water. Simmer for 5 minutes until the sauce reaches a saucy but not thick consistency—Bengali jhol-style sauces are meant to be lighter than Italian ragù. Stir in chopped cilantro. Taste and adjust seasoning.

Cook and Serve

Bring a large pot of well-salted water to a gentle boil. Add gnocchi in batches without crowding. Cook until they float to the surface, then continue cooking for 30 seconds more. Remove with a slotted spoon directly into the sauce.

Gently toss the cooked gnocchi in the Bengali tomato sauce over low heat for 1 minute to coat and absorb flavors. Divide among warm bowls.

Drizzle each serving with a small amount of raw mustard oil (this adds an authentic Bengali punch), scatter with fresh cilantro leaves, and add a pinch of dried red chili flakes if desired. Serve immediately.