(such as flat-leaf parsley leaves, tarragon leaves, arugula, mizuna, and baby mustard greens).
Add the 2 cups of water and bring to a boil.Simmer over moderately low heat, without stirring, until the mung beans are tender and the water has evaporated, about 20 minutes..
Meanwhile, in a medium saucepan, heat 1 inch of vegetable oil to 325°.Add half of the sliced onions and fry, stirring occasionally, until browned and crisp, about 7 minutes.Using a slotted spoon, transfer the onions to paper towels to drain.
Repeat with the remaining onions..In a small skillet, melt the remaining 1 tablespoon of butter.
Add the cumin seeds and dried chiles and cook over moderately high heat until fragrant, about 30 seconds.
Scrape the cumin-chile butter into the mung beans and stir in the lemon juice, cilantro and tomato; season with salt.(Batter may look slightly broken; do not overmix.).
Reduce speed to medium-low, and add flour mixture to butter mixture, one-third at a time, beating for 15 seconds after each addition, stopping as necessary to scrape down sides of bowl to ensure all flour is incorporated.. Scoop 1/2 cup batter into a small bowl, and whisk in 2 tablespoons rum.Add rum batter back to remaining batter, and stir to combine.
(Dough may not be completely smooth; do not overmix.).Spoon batter into prepared pan, and tap pan against counter to distribute evenly.