Preheat oven to 200 degrees. Pat fish dry with paper towels. Season on both sides with salt and pepper.
Heat oil in a large skillet over medium-high heat until just smoking. Sauté fish in a single layer without moving until crispy and golden-brown on one side, 2 to 3 minutes.
Flip each piece of tilapia and continue cooking until fish is 145 degrees. Transfer fish to oven to keep warm.
To the same skillet, add onions and garlic and sauté 1 minute. Add peppers and sauté until softened, 1 to 2 minutes.
Stir in tomatoes, capers, and thyme until heated through, about 1 to 2 minutes.
Stir in lemon juice and add salt and pepper to taste. Return fish to pan and stir to coat with sauce.
Tilapia: Protein-rich tilapia is one of the most affordable and quick-cooking protein options available. Find it at the fish counter or frozen, and look for it with either farm-raised or wild tilapia label. (Wild is my personal preference when I can find it.)
Bell peppers: I prefer a mix of colors, but any single hue will do, too. Yellow, red, orange, green-yellow; choose one or a variety.
Yield: This fish recipe makes four 6-ounce, entree-sized servings.
Storage: Store leftovers covered in the refrigerator for up to 4 days.