Heat the olive oil in a large non-stick skillet over medium-high heat until shimmering.
Add the diced yellow onion and sliced bell peppers to the pan, sautéing for 5-7 minutes until the edges are slightly charred and tender.
Push the vegetables to the side and add the ground beef, using a wooden spoon to break the meat into small crumbles.
Once the beef is mostly browned, sprinkle in the chili powder, cumin, garlic powder, onion powder, sea salt, and black pepper.
Pour in the tablespoon of water and stir everything together, allowing the spices to bloom and coat the beef and peppers evenly.
Add the fresh baby spinach to the skillet and toss for 1 minute until the leaves are just wilted but still bright green.
Remove from heat and transfer the mixture to a shallow bowl for a clean, protein-packed meal.