An Italian spinach salad gets its flavor from blood oranges, fennel, and red onion; cremini mushrooms and spinach add an earthy note.
Make the vinaigrette: Using a sharp paring knife, peel 2 oranges, following the curve of the fruit; cut between membranes to remove whole segments. Place in a small bowl; set aside. Juice remaining orange into a separate small bowl or large glass measuring cup; whisk in lemon juice, vinegar, and salt. Season with pepper; set aside.
In a small skillet, cook bacon over medium heat until crisp and browned on both sides, about 4 minutes per side. Transfer to drain on paper towels; let cool, and finely crumble.
In a large serving bowl, combine fennel, mushrooms, onion, and spinach. Add reserved orange segments and vinaigrette, and toss to combine. Divide among serving plates, and sprinkle each with crumbled bacon.
If fresh is unavailable, look for packages of pre-washed baby spinach. Blood oranges are named for their vivid red-streaked flesh.