Warm Spinach Salad · Bacon Vinaigrette, Mushrooms, Pickled Red Onions
This is a classic warm spinach salad. The bacon vinaigrette gets poured over fresh baby spinach while it’s still hot, wilting the leaves just enough without turning them mushy. Sautéed mushrooms add earthiness, crispy bacon adds crunch and salt, and pickled red onions bring acidity and brightness. Everything comes together warm – not hot, not cold – which makes this salad feel more substantial than a typical cold salad.
The key is the bacon vinaigrette. You cook bacon until it’s crispy, use some of the rendered fat to sauté mushrooms and shallots, then make a warm vinaigrette with more of that bacon fat, vinegar, and Dijon. The hot vinaigrette wilts the spinach slightly and coats every leaf. This is the kind of salad that works as a light dinner on its own or as a side to grilled steak or roasted chicken.
Warm Spinach Salad · Bacon Vinaigrette, Mushrooms, Pickled Red Onions
Baby spinach wilted with warm bacon vinaigrette, sautéed mushrooms, crispy bacon, and pickled red onions.
Ingredients
Method
Cook the Bacon
- Cook the bacon in a large skillet over medium heat until crispy, about 8-10 minutes, flipping occasionally. You want it deeply browned and crispy enough to crumble. Transfer the cooked bacon to a paper towel-lined plate to drain and cool.
- Pour the rendered bacon fat into a heatproof measuring cup or small bowl. You should have about 1/2 cup of fat. Reserve 1/4 cup for the vinaigrette and use the rest for cooking the mushrooms.
- Once the bacon is cool enough to handle, crumble or chop it into bite-sized pieces. Set aside.
Sauté the Mushrooms
- Return about 2 tablespoons of the bacon fat to the same skillet over medium-high heat. Add the quartered mushrooms in a single layer. Don’t crowd them – if your pan isn’t big enough, cook them in batches.
- Let the mushrooms cook undisturbed for 2-3 minutes until they develop a golden-brown crust on one side. Stir or toss them and continue cooking for another 3-4 minutes until they’re browned and tender. Season with a pinch of salt and pepper.
- Transfer the cooked mushrooms to a plate and set aside. Keep them warm.
Make the Bacon Vinaigrette
- In the same skillet (no need to wipe it out – those browned bits add flavor), add the remaining 1/4 cup of bacon fat. Heat over medium heat until the fat is warm.
- Add the minced shallots and cook for 1-2 minutes, stirring frequently, until they’re softened and fragrant. Don’t let them brown too much – you want them tender and sweet.
- Remove the skillet from the heat. Add the red wine vinegar, Dijon mustard, and honey (if using). Whisk everything together until emulsified and smooth. The vinaigrette should be warm, not screaming hot. Taste and season with salt and pepper. It should be tangy, savory, and slightly sweet.
Assemble the Salad
- Place the baby spinach in a large mixing bowl – one big enough to toss everything comfortably.
- Pour the warm bacon vinaigrette over the spinach while it’s still warm. Immediately toss the spinach with tongs or your hands, making sure every leaf gets coated with the vinaigrette. The heat will wilt the spinach slightly – it should soften but still have some body. Work quickly so the spinach wilts evenly.
- Divide the dressed spinach among four plates or shallow bowls. Top each serving with the sautéed mushrooms, crumbled bacon, and a generous spoonful of pickled red onions. Finish with a crack of black pepper.
Serve
- Serve immediately while the salad is still warm. The contrast between the warm spinach and vinaigrette and the cool pickled onions is part of what makes this salad special.
Notes
The warm bacon vinaigrette is the star here. Bacon fat is flavorful and adds richness, but it also emulsifies beautifully with vinegar and mustard to create a smooth, coating dressing. Pouring it warm over the spinach wilts the leaves just enough – they soften and become more tender without turning to mush like they would if you cooked them in a pan.
Using the same skillet for bacon, mushrooms, and vinaigrette builds layers of flavor. Each step picks up the fond (browned bits) from the previous step. By the time you make the vinaigrette, that skillet has bacon flavor, mushroom flavor, and caramelized bits that all get incorporated into the dressing.
The pickled red onions cut through the richness of the bacon fat and add brightness. Without them, this salad would feel heavy. The acidity and sweetness of the pickled onions balance everything out.
Timing is Everything
This salad needs to be assembled and served immediately. You can prep all the components ahead – cook the bacon, sauté the mushrooms, wash and dry the spinach – but don’t dress the salad until you’re ready to eat. Once the warm vinaigrette hits the spinach, you have about 2-3 minutes before it starts to wilt too much and turn limp.
If you’re making this for guests, have everything ready to go and make the vinaigrette at the last minute. It only takes 2-3 minutes to warm the bacon fat, cook the shallots, and whisk in the vinegar and mustard.
Spinach Prep
Baby spinach is best for this salad – the leaves are tender and wilt easily. Mature spinach has tougher stems and thicker leaves that don’t respond as well to the warm dressing.
Make sure the spinach is completely dry before dressing it. Wet spinach will dilute the vinaigrette and make the salad watery. If you wash your spinach, spin it dry in a salad spinner or pat it thoroughly with paper towels.
Mushroom Tips
Quartering the mushrooms gives you more surface area for browning. Whole or halved mushrooms don’t get as much caramelization. Cut them into quarters through the stem so each piece has some stem and cap.
Don’t stir the mushrooms too much when they first hit the pan. Let them sit and develop a golden crust before tossing them. Mushrooms release water as they cook – if you stir constantly, they’ll steam instead of brown. Give them a chance to caramelize.
Bacon Fat
You need enough bacon fat to make this salad work. Eight slices of bacon should give you about 1/2 cup of rendered fat, which is perfect. If you end up with less, supplement with olive oil or butter.
If you have extra bacon fat, save it. Store it in a jar in the refrigerator and use it for cooking eggs, sautéing vegetables, or making another batch of this vinaigrette.
Vinaigrette Balance
The ratio for the vinaigrette is about 2 parts fat to 1 part acid (red wine vinegar). This is more acidic than a typical vinaigrette because the bacon fat is so rich. You want enough acidity to cut through the fat and brighten the salad.
The Dijon mustard helps emulsify the dressing and adds a subtle tang. The honey is optional but recommended – it balances the vinegar and rounds out the flavors without making the dressing sweet.
Taste your vinaigrette before pouring it over the spinach. It should be tangy, savory, and well-balanced. If it’s too sharp, add a bit more honey or bacon fat. If it’s too rich, add a splash more vinegar.
Scaling Up or Down
This recipe serves 4 as a side salad or light lunch. To scale up, multiply the ingredients proportionally. The vinaigrette comes together quickly, so making a double batch doesn’t add much time.
For individual plating at a dinner party, dress the spinach in the large bowl, then divide among plates and top with mushrooms, bacon, and pickled onions. For family-style service, toss everything together in the bowl and bring it to the table.
Make-Ahead Components
Cook the bacon up to a day ahead. Store it wrapped in paper towels in the refrigerator and crisp it briefly in a warm oven before serving.
Sauté the mushrooms up to a few hours ahead. Keep them at room temperature and rewarm briefly in a skillet before assembling the salad.
Wash and dry the spinach up to a day ahead. Store it wrapped in paper towels in a sealed container in the refrigerator.
Don’t make the vinaigrette ahead – it needs to be warm when you pour it over the spinach.
