Cook the lentils: Drain the lentils that have been soaking, and add to a pressure cooker/Instant Pot or Saucepan with water.
Pressure Cook: Close the lid and cook for 11 to 12 minutes at high pressure setting. (Or 2 whistles over high heat, them simmer for 8 minutes over low heat). Let the pressure release naturally.
Saucepan: Partially cover and cook over medium heat for 20 minutes. Reduce heat to medium-low and simmer for 10 minutes, or until tender.
Meanwhile, heat oil in a skillet over medium heat. When hot, add mustard seeds and wait for them to start sputtering. (A few seconds if the oil is hot enough).
Add onion, garlic, chile and cook until translucent. About 5 minutes. Stir occasionally.
Meanwhile, grind all the spices together in a small blender, spice grinder or mortar and pestle. Add to the skillet. Mix and cook for a minute.
Add tomatoes and bell pepper and a splash of water and cook until tomatoes are tender. 4 to 5 mins.
Add this to the simmering lentils. Use a bit of water to swirl around on the skillet to pick up any leftover spices and add to the simmering lentils. (Alternatively, if you have cooked lentils, add the lentils to the skillet. Add water if needed to adjust consistency).
Add salt and broccoli and bring to a boil over medium heat. Continue to cook for 2-3 mins. Taste and adjust salt and heat. Add more water if needed or simmer longer for desired consistency. Cover and let sit for another 2 mins before serving. Garnish with cilantro and lemon if needed. I also often use coconut shreds and cayenne/pepper flakes for garnish. Serve as soup or over rice/quinoa.