Boil greens (all) until just wilted, not stewed. Drain. Set aside. Allow to cool.
Add about 1 tablespoon butter or ghee to large skillet. Fry cumin (and fenugreek seeds if not using fresh fenugreek) until fragrant. Add onion and fry until soft. Add ginger and garlic; fry until very fragrant. Add tomatoes, garam masala, cayenne, and turmeric. Saute until soft, blended, lovely.
Blend cooled wilted greens with cream in blender or food processor. Add this mixture to the skillet mixture; add salt and pepper. Cover and simmer 15 minutes.
IF you can figure out how to fry paneer, then fry it then add to mixture as it simmers. If, like me, you cannot master frying paneer without it melting all over the pan into a soupy consistency, save the cheese until the end.
Here's how they say you can fry your paneer:
Cube the paneer to about 1" dimensions
large skillet; heat over medium-high heat. Preferably a steep pan. When a drop of water rolls over the pan without steaming or the like, the pan is hot enough (in other words, it needs to bead).
Add about 1 - 2 teaspoons coconut oil. Once the oil separates from the bottom of the pan, turn down heat to medium. Put the paneer in a single layer in the pan. Once you can move the cubes around easily (they aren't sticking any longer), the cube is done on that side; flip it over. You want to do this 6 times (each side of the cube). Or, at least 4 sides. Good luck!
Most home cooks make the mistake of overcooking greens until they turn a dull, muddy olive drab. Vibrant green saag requires flash blanching followed by rapid cooling. Boiling spinach, kale, and fenugreek leaves only until just wilted stops the heat degradation of chlorophyll. Plunging them into cold water halts internal cooking immediately.
The Chemistry of Spicing and Aromatics
Building flavor starts with blooming whole spices in hot fat. Cumin seeds and fenugreek release fat-soluble essential oils when exposed to heat. Fat acts as a solvent for these aromatic compounds, distributing them evenly throughout the dish. Adding onions, ginger, and garlic next builds a moisture base. As the onions soften, natural sugars caramelize. Spices like turmeric and garam masala then dissolve into the lipid phase, bonding their flavor molecules to the oil rather than sinking into the watery vegetable purée.
Blending and Emulsifying the Greens
Pureeing the cooked greens with heavy cream creates an emulsion. Dairy fats coat the tongue, which softens the natural bitterness of oxalic acid found in spinach and kale. Simmering this mixture for 15 minutes allows the proteins to bind.
Handling and Frying Paneer
Paneer has a high casein protein content and virtually no melting lactose, which makes it structurally unique. Getting a golden crust requires a pan heated until water droplets bead and dance across the surface. Adding high-smoke-point oil prevents burning while the exterior proteins dehydrate and brown. Flipping the cubes on four to six sides develops a chewy exterior while keeping the interior dense and milky. Dropping the cheese straight into the simmering sauce allows it to absorb the spiced cream without turning rubbery.