Heat a heavy pan on low flame. Add almonds and roast, stirring often, for 4-5 minutes until nutty and skin looks slightly tightened.

Add cashews and roast for 2 minutes. Add pistachios and chironji (if using) for 1 more minute. Everything should be lightly golden and fragrant. Do not let them darken.

Spread the roasted nuts on a plate and let cool for at least 15 minutes. Blending warm nuts will turn them into nut butter, not powder.

In the same warm pan (off the flame), add the saffron and let it sit for 30 seconds. Residual heat is enough to dry it so it grinds cleanly.

Add the cooled nuts and saffron to a blender or spice grinder. Blend in short 10-second pulses so the powder stays cool and does not heat up and clump. Stop when you have a fine, even powder with no large pieces. If the blender gets warm, stop and let it rest for a minute.

Transfer the nut powder to a bowl. Add cardamom, fennel seeds, nutmeg (if using), and sweetener (if using). If making the millet-boosted version, add the ragi or foxtail millet powder now. Mix well with a clean dry spoon. Taste a pinch and adjust cardamom or sweetness to your preference.

Funnel into a clean, dry glass jar with a tight lid.