For the paneer: Preheat oven to 450 degrees F. Spread ricotta cheese in a rimmed baking sheet lined with parchment paper so it's about the thickness of a French fry. Bake for 50 minutes.
For the saag: In a large pot, bring two inches of water to a boil. Add the spinach, cover, and steam until wilted, about 5 minutes. Drain and place in a food processor, then purée until smooth; set aside. Add 2 tablespoons canola oil to a wok or kadai, then add cumin, chilies, fennel, cloves, cardamom and asafoetida. Turn heat to medium to “bloom” the spices until they are fragrant and jumping, about 5 minutes. Add ginger; stir and continue cooking until aroma is released and its texture is slightly crispy, 1-2 minutes. Add puréed spinach (with 1-2 tablespoons of water, optional, to remove the spinach from the food processor). Add salt and continue mixing; then turn off the heat, cover, and set aside.
Add the fenugreek and 2 tablespoons canola oil to a small skillet and place over medium heat to roast. Add 1-2 tablespoons water; stir and continue cooking until it sizzles and releases a slightly bitter aroma, 2 minutes. Add to spinach mixture, stir and set aside. Remove the paneer from the oven and cut into 1-inch squares.
Add 1 tablespoon canola oil to a nonstick skillet; over medium heat, fry the paneer cubes in a single layer until crispy, about 2 minutes. Remove from heat and set aside. For the tempering oil: In the small saucepan, heat the ghee over medium heat; then add cumin, fennel, chilies, and asafoetida and cook until fragrant, about 2 minutes. Add cayenne pepper and 1 teaspoon of water (to keep the cayenne from burning) and set aside.
Place saag in a serving bowl, then top with paneer cubes, followed by more spinach. Spoon tempering oil over the top before serving.