In a large bowl, rinse and soak the red lentils for around 4 hours or overnight. Be sure to cover the lentils with enough water as they are going to soak up quite a bit. Once soaked, drain and rinse thoroughly. Set aside.
For this recipe, it is best to have everything prepped in bowls before you start to cook. Mix together the spice blend and chop all ingredients and have them ready to go. You don't want to be scrambling looking for spices once you start cooking.
Place a large pot over medium heat. Once hot, add the vegan butter and melt until bubbly. Then add the carrots, onions, celery, ginger, and chili pepper. Sprinkle with a little salt and pepper. Let cook down for about 10 minutes, stirring every so often.
After the veggies have cooked down, add the spice blend and toast the spices and veggies over medium heat, mixing thoroughly. Add a splash of water to help the bottom from sticking and then add the garlic. Cook for a few more minutes, until the mixture smells outrageously fragrant.
Add the lentils, water, cherry tomatoes, tamari, yellow mustard, garlic powder, and salt, to taste. Turn the heat up to medium-high and bring to a boil. Once to a boil, reduce the heat to medium-low and cook at a simmer with a cracked lid. Cook down for about 30 minutes, stirring every so often, until the tomatoes and lentils become super tender.
When ready to serve, add the spinach and mix well. Once the leaves become wilted, give the dahl a taste. At this point, you can add more cayenne pepper or Thai chili if you like it to be spicer. Ladle over some rice and garnish with coconut yogurt, sliced avocado, and chopped cilantro. Serve with a piece of toasted bread or pita and a slice of lime.