Heat oil in a large sauce pan over medium. Slice mushrooms, chop onion, and mince garlic.
Add mushrooms and onions to hot oil, and cook for 6-8 minutes, stirring often. Add garlic and cook for 1-2 minutes longer.
Turn heat down to medium-low, cover, and continue to cook for 10 minutes, stirring occasionally to avoid sticking to the pan.
Add tomato paste, paprika, 2 tablespoons fresh lemon juice, cumin, and salt. Stir to combine while adding water; bring to a boil.
Add quinoa, reduce heat to low, cover, and simmer for 15 minutes or until the water has been absorbed. Remove from heat, allow to sit for 2-3 minutes, then fluff with a fork.
Add spinach to each serving plate and then top with quinoa. Cut remaining lemon into wedges for spritzing.
Serve strawberries on the side.