In a small sauce pan, combine 1/2 cup water, quinoa, and garlic. Bring to a boil then reduce heat and simmer until quinoa is tender and most of the liquid has been absorbed, about 15 minutes. Take off the heat and add olive oil, basil, and salt, to taste.

Meanwhile, rub each side of the tilapia filets with chili powder, paprika, and cayenne pepper. Place a medium-size nonstick skillet over medium-high heat and bring 1 1/4 cups water to a boil. Add tilapia and tomatoes, cover and cook 3 minutes. Add arugula, recover, and cook until tilapia flakes easily with a fork, about 2 minutes.

When ready, divide quinoa between two plates. Then, reserving the liquid in the skillet, remove the tilapia and vegetables and divide between the plates. Whisk butter, lemon juice, and capers into the reserved liquid until butter has melted. Season with salt and pepper, if desired and drizzle over tilapia.

Remove skillet from heat and add butter, lemon juice, and capers. Whisk until butter has melted. Season with salt and pepper, to taste, then drizzle over tilapia to serve.