1 cup (8 ounces) dried whole black gram beans
1 large ripe tomato
1 tablespoon grated peeled fresh ginger
3 cloves garlic, minced
½ medium-size onion, minced
1 tablespoon tomato paste
2 teaspoons ground coriander
1 teaspoon salt, or more to taste
½ teaspoon ground black pepper, or more to taste
¼ teaspoon cayenne pepper, or more to taste
6 tablespoons unsalted butter
½ cup heavy (whipping) cream
1. Spread out the beans on a baking sheet and pick out and discard any twigs or stones. Place the beans in a large bowl and add cold water to cover by 3 inches. Swirl the beans with your fingers, then place them in a strainer to drain. Repeat the process another 3 or so times.
2. Place the beans in a pressure cooker and add 4 cups of water. Pressure cook the beans over medium heat until you hear an even hiss and the valve in the lid dances in a lively fashion, about 10 minutes.
3. Meanwhile, core the tomato and cut it into chunks. Place the tomato in a food processor and process until pureed.
4. Run cold water over the pressure cooker for 5 minutes to cool it completely (both top and sides), then remove the lid.
5. Stir the ginger, garlic, onion, pureed tomato, tomato paste, coriander, salt, black pepper, cayenne, and 4 tablespoons of the butter into the beans. Pressure cook the beans again until they are reduced to a thick, creamy puree, about 5 minutes (see Note). Once again, cool the cooker
completely under cold running water before removing the lid.
6. Shortly before serving, stir the cream into the beans and let them simmer gently in the pressure cooker (with its lid off) or in a saucepan until rich and creamy, 2 minutes. Taste for seasoning, adding more salt, black pepper, and/or cayenne as necessary. Transfer the beans to a serving bowl
and dot the top with the remaining 2 tablespoons of butter. Serve the beans at once.
NOTE: The beans can be prepared several hours or even a day ahead to this point and stored, covered, in the refrigerator. Reheat them over medium heat, stirring well.