Instant Pot Keto Zuppa Toscana: The Best Thickener That Isn’t Flour

Creamy, cozy Zuppa Toscana is the kind of soup that makes you want to cancel plans and live in a blanket. The only problem? Traditional thickeners (hello, flour) don’t exactly fit the keto vibe.

This Instant Pot version keeps the comfort, keeps it low-carb, and uses the best thickener that isn’t flour: cauliflower. It blends into the broth like a dream, making it rich and velvety without tasting like “healthy soup.”

Why You’ll Love This

It’s fast, filling, and legit creamy without flour or cornstarch—plus the Instant Pot makes it weeknight-easy while still giving you that slow-simmered flavor.

Ingredients

• 1 lb Italian sausage (spicy or mild), casings removed if needed
• 4 slices bacon, chopped
• 1 medium yellow onion, diced
• 3–4 cloves garlic, minced
• 4 cups chicken broth
• 1 small head cauliflower, cut into small florets (about 4–5 cups)
• 1 medium russet potato substitute: 1 cup diced daikon radish (optional, for that “potato-ish” bite)
• 1 tsp salt (start with 1/2 tsp if your broth is salty)
• 1/2 tsp black pepper
• 1/2 tsp crushed red pepper flakes (optional, to taste)
• 1 cup heavy cream
• 3 cups chopped kale (stems removed)
• 1/2 cup grated Parmesan, plus more for serving
• 1 tbsp lemon juice (optional, for brightness)

How to Make It

1. Set the Instant Pot to Sauté. Add the chopped bacon and cook until crisp, 5–7 minutes. Scoop bacon out with a slotted spoon and set aside, leaving the drippings in the pot.
2. Add Italian sausage to the pot. Break it up and brown until mostly cooked through, about 4–5 minutes. If there’s a lot of grease, spoon off a little (leave some for flavor).
3. Add onion and cook 2–3 minutes until softened. Stir in garlic and cook 30 seconds, just until fragrant.
4. Press Cancel. Pour in a splash of chicken broth and scrape up any browned bits on the bottom (this helps prevent a burn notice). Add remaining broth, cauliflower florets, and diced daikon (if using). Season with salt, pepper, and red pepper flakes.
5. Lock the lid and set to Pressure Cook (High) for 4 minutes. Once done, let it Natural Release for 5 minutes, then carefully Quick Release the rest.
6. Open the lid. Use an immersion blender to blend part of the soup right in the pot until the broth looks creamy and thick (about 20–40 seconds). Want it thicker? Blend a bit more. Want it chunkier? Barely blend.
7. Stir in heavy cream and Parmesan until smooth. Turn on Sauté (Low) if you need a little heat to help it melt in.
8. Add kale and stir until wilted, 1–2 minutes. Taste and adjust seasoning. Finish with lemon juice if you want that “wow why is this so good” pop.
9. Serve topped with the reserved bacon and extra Parmesan.

Tips for the Best Results

• Cauliflower is the thickener. Blending cooked cauliflower into the broth gives you that creamy body without flour, gums, or mystery powders.
• Don’t skip deglazing. Scrape the browned bits after sautéing to avoid the Instant Pot burn warning.
• Control the thickness. Blend more for a thicker soup, less for a brothy vibe. You’re in charge.
• Add dairy after pressure cooking. Heavy cream can separate under pressure; stirring it in at the end keeps things silky.
• Kale goes in last. It stays bright and tender instead of turning army-green and overcooked.
• Salt at the end. Sausage, bacon, broth, and Parmesan all bring salt—taste before adding more.

Variations

• Extra spicy: Use hot Italian sausage and increase red pepper flakes, then finish with a pinch of cracked black pepper.
• Super thick “stew” style: Add an extra 1–2 cups cauliflower and blend more aggressively.
• Dairy-light (still keto-ish): Swap heavy cream for full-fat coconut milk (it will have a faint coconut note) and use nutritional yeast instead of Parmesan if needed.
• More veggies: Add sliced mushrooms or chopped zucchini after pressure cooking (on Sauté) so they don’t over-soften.
• No daikon: Skip it entirely and lean into the kale + sausage + creamy broth situation, or add a few chopped radishes for a similar bite.

Storage & Reheating

Store leftovers in an airtight container in the fridge for up to 4 days. Reheat gently on the stovetop over medium-low or in the microwave in 30–45 second bursts, stirring between rounds; if it thickens too much, splash in a little broth. For best texture, freeze without the kale and add fresh kale when reheating (up to 2 months frozen).

FAQ

What’s the best thickener that isn’t flour for keto Zuppa Toscana?

Cooked cauliflower, blended into the broth. It naturally thickens the soup and makes it creamy without adding flour, cornstarch, or extra carbs. It also tastes neutral once it’s mixed with sausage, bacon, garlic, and Parmesan.

Do I have to use an immersion blender?

It’s the easiest option, but not required. You can ladle 2–3 cups of the soup (with plenty of cauliflower) into a blender, blend until smooth, then stir it back in. Just vent the lid and blend carefully since it’s hot.

Why add the cream after pressure cooking?

Dairy can separate or curdle under high pressure. Stirring heavy cream in at the end keeps the soup silky and consistent, and it also lets you control the final richness.

Can I make this thicker without adding more cauliflower?

Yes. Blend more of the existing soup, then simmer on Sauté for a few minutes to reduce slightly. Parmesan also helps thicken as it melts, so adding an extra tablespoon or two can boost body (and flavor).

How do I keep the kale from getting mushy in leftovers?

Add the kale right before serving, or store it separately and stir it into individual bowls after reheating. If the kale is already mixed in, reheat gently and stop as soon as it’s hot to avoid overcooking it.