In a medium saucepan, bring water to a boil. Add quinoa, reduce heat to low, cover, and simmer for 15 minutes until water is absorbed. Fluff with a fork and set aside.
While quinoa cooks, heat 1 tablespoon of olive oil in a large skillet over medium heat. Add shrimp, salt, and black pepper, cooking for 2-3 minutes per side until pink and cooked through. Remove shrimp from the skillet and set aside.
In the same skillet, add remaining olive oil and garlic. Cook until fragrant, about 1 minute.
Stir in the spinach and red pepper flakes; cook until spinach is wilted, about 2 minutes.
Return shrimp to the skillet, add lemon juice, and toss everything to combine well.
Serve the shrimp and spinach mixture over a bed of quinoa. Enjoy hot!