In a small bowl combine tomatoes, red onion, cilantro, lime juice and 1 tablespoon evoo, mix well and set aside.

Heat 1 tablespoon evoo in a large cast iron or nonstick skillet over medium-high heat until shimmering. Add spinach and garlic, season with salt, and cook, stirring, until wilted, about 1 minute. Squeeze out any accumulated liquid and transfer to a bowl.

Add black beans and cheese to spinach and mix to combine. Spread a heaping ¼ cup mixture evenly over half of one tortilla, leaving a 1/2-inch border. Fold tortilla over and seal edges by pressing down firmly. Repeat with remaining filling and tortillas.

Heat remaining 3 tablespoons evoo in same skillet over medium heat until shimmering. Carefully add folded tortillas and cook until golden brown on first side, about 2 minutes. Flip quesadillas, season with salt, and continue cooking until golden brown and puffy on second side, about 2 minutes longer.

Transfer quesadillas to a paper towel to drain. Cut into triangles and serve immediately with tomato salad.