This colorful salad is chockfull of taste and texture. The warm dressing wilts the greens, making it particularly suitable for fall and winter meals. To turn it into a main dish suitable for lunch or a light supper, add some sliced leftover roast chicken.
Brown the bacon in a skillet over medium heat, stirring occasionally, until crisp, about 10 minutes. Using a slotted spoon, transfer to a paper-towel-lined plate to drain; leave the bacon fat in the skillet.
Add vinegar and oil to the skillet; whisk, scraping up browned bits from bottom of pan. Season with salt and pepper to taste.
Meanwhile, divide the spinach among four salad plates; scatter the onion, radishes, mushrooms, tomatoes and eggs over the greens. Divide dressing evenly among salads and serve right away.