Cook quinoa: Dry toast the quinoa in the saucepan over medium-high heat for 2-3 minutes. Add water or broth and a pinch of salt. Bring to a boil over high heat. Reduce heat, cover, and simmer until the liquid is absorbed (~15 minutes). Look for a white ring that pops out when the quinoa is cooked. Remove from heat and let rest, covered, for 10 minutes.
While quinoa is cooking, heat a 10-12” skillet over medium heat. Add oil. Once oil is shimmering, add onion and sauté until translucent, ~5 minutes.
Add ground beef and sprinkle with ¼ teaspoon salt. Use a spatula to break apart into smaller pieces. Cook until mostly brown and the beef begins to release some juices. Add garlic, chili powder, cumin, and paprika. Cook for ~1 minute.
Add lentils and salsa. Cook for 3-5 minutes until lentils are heated through and beef browns completely. Add more salt to taste.
Fluff quinoa with fork. Assemble bowls with leafy greens, quinoa, beef-lentil mixture, and toppings to your taste. Enjoy!