Make the tomato puree, if using, see Notes for instructions and set aside.
Par-cook the lentils by bringing a pot water to boil. Add lentils and boil 10 minutes. Turn off heat and let sit for roughly 30 minutes. Drain lentils & set aside.
Prepare the chile-garlic-ginger paste by grinding together with a mortar & pestle. Set aside.
Once the above is prepped, add the par-cooked lentils & 3 cups vegetable broth [or water] to crockpot with first 2 tbsp butter, and the chile-garlic-ginger paste. Add in spices [salt, nutmeg, garam masala, cumin, fenugreek leaves & powder, chile powder, aamchoor powder, kati salt, coriander & cinnamon] and tomato puree.
Let everything cook on low for 8 hours.
Before serving, add the red kidney beans, half & half and remaining 2 tablespoons of butter. Salt to taste. Let cook an additional 30 minutes.
If you like your dal a little less thick, stir in an additional ½ to 1 cup vegetable broth [or water].
Serve over rice & garnish with cilantro.
The ingredient list hides the physical transformation that occurs when whole urad dal meets acidic tomato puree over an extended period. Acid slows the softening of legume skins. Par-cooking the lentils for ten minutes followed by a thirty-minute rest overcomes this barrier. Crushing the ginger, garlic, and dry chiles together in a mortar and pestle ruptures cell walls to release volatile oils before they enter the slow cooker.
Long-Term Storage and Freezing Dynamics
Lentils and kidney beans absorb liquid continuously as they cool. Store leftovers in airtight glass containers for up to four days in the refrigerator. Freeze portions for up to three months without losing structural integrity. Thaw frozen dal overnight in the refrigerator before reheating. Add up to one cup of vegetable broth during reheating to restore the original consistency, because starches continue to bind available moisture.
Accompaniments and Pairing Logic
Serve this rich preparation over steamed basmati rice to provide a neutral starch counterweight. The grains absorb excess fat and spiced butter. Garnish with fresh cilantro just before eating to introduce volatile herbal brightness against the heavy, slow-simmered base.