Put oil, garlic and paprika into a large frying pan. Put over medium heat, stirring until warm and fragrant. Increase heat to high. Add mushrooms. Cook, stirring occasionally for about 5 minutes, or until mushrooms are light golden.
Wash beans then add to mushrooms. Cover with lid. Cook for about 1-2 minutes, or until beans are tender crisp. Add tomatoes, toss over high heat for 1 minute until warm. Squeeze over lemon juice and toss to combine. Season and serve.