Add olive oil to a skillet over medium heat. Once hot, add sweet potato and season with salt and pepper. Sauté until almost tender, 7-10 minutes. Add cauliflower and garlic, season with a bit more salt and pepper, and sauté until tender, about 5 minutes. Remove from heat.
Add mixture to a large bowl. Add cooked lentils and pistachios, and allow the mixture to cool. You can stick the bowl in the fridge/freezer to speed this up.
Once fairly cool, add your herbs and dressing. Toss well to combine. Serve at room temperature or cool. It’s seriously so good you guys.