Keto Mushroom & Walnut Bolognese with Zucchini Noodles
This vegan keto mushroom and walnut bolognese swaps classic ground meat for finely chopped white mushrooms and walnuts. Together they create a surprisingly meaty texture with deep umami flavor, served over spiralized zucchini noodles instead of spaghetti. The walnuts deliver fat and omega-3 fatty acids, the mushrooms add depth and savoriness. Just 7 g net carbs per serving with 36 g fat and 12 g protein, ready in 25 minutes.
Key facts at a glance
- Prep time: approx. 25 minutes, one pan for the sauce and a spiralizer for the zucchini.
- Approx. 7 g net carbs and 36 g fat per serving.
- Ingredients: white mushrooms, walnuts, tomato passata, olive oil, garlic, zucchini, oregano.
- Vegan, savory and designed as a complete keto meal; pasta feeling without the pasta.
Ingredients
One serving is designed as a complete vegan keto meal; pasta feeling without the carbs.
| Amount | Ingredient | Note | ||
|---|---|---|---|---|
| white mushrooms | finely chopped | |||
| finely chopped | ||||
| walnuts | finely chopped | |||
| finely chopped | ||||
| tomato passata | - | |||
| olive oil | 1 tbsp, for the sauce | |||
| 1 tbsp, for the sauce | ||||
| garlic clove | chopped | |||
| chopped | ||||
| dried oregano | 1 tsp | |||
| 1 tsp | ||||
| zucchini | spiralized | |||
| spiralized | ||||
| olive oil | approx. 1 tsp; for the zoodles | |||
| approx. 1 tsp; for the zoodles | ||||
| nutritional yeast | for topping | |||
| for topping | ||||
| salt | to taste | |||
| to taste | ||||
| pepper | to taste | |||
| to taste | ||||
| fresh basil | for garnish | |||
| for garnish | ||||
Preparation
Finely chop the mushrooms and walnuts (knife or food processor, do not puree). Sear in olive oil over high heat until all the liquid has evaporated. Add garlic and oregano, then stir in the tomato passata and let it reduce for 10 minutes. Spiralize the zucchini into noodles and toss briefly in a separate pan with olive oil. Spoon the bolognese over the zoodles.
Why this bolognese works as vegan and keto
Traditional bolognese with spaghetti easily reaches 60 to 80 g net carbs per serving from the pasta alone. Zucchini noodles (200 g) bring only 3 g net carbs. The sauce itself is also low carb: 50 g of walnuts provide 33 g fat and just 1.5 g net carbs, and 150 g of white mushrooms contain about 0.5 g net carbs. Tomato passata (50 ml) adds roughly 2 g net carbs, used sparingly it still gives plenty of tomato flavor. The umami punch of the mushrooms combined with the texture of the chopped walnuts creates a mouthfeel that really does evoke real ground meat.
Source: USDA FoodData Central – Mushrooms, white, raw , Harvard Nutrition Source – Nuts for the Heart
Walnuts: fat, protein and omega-3
Walnuts are the only tree nut with a meaningful amount of alpha-linolenic acid (ALA), a plant-based omega-3 fatty acid. Per 50 g they deliver about 33 g fat, 7.5 g protein and just 1.5 g net carbs. Finely chopped, they soak up the tomato sauce and mimic the texture of ground meat.
White mushrooms: natural umami without carbs
White mushrooms contain naturally occurring glutamate, the same flavor compound that gives meat its savory character. 150 g of raw white mushrooms have only about 0.5 g net carbs. When seared hard, the moisture evaporates and the umami flavor concentrates.
How do I serve and vary this mushroom and walnut bolognese?
Plate the zoodles in a deep bowl and spoon the bolognese on top. Nutritional yeast and fresh basil as a topping round out the dish. In practice the bolognese tastes best when the mushroom and walnut mix is browned really dark, that is where the deepest layer of flavor comes from.
Meal prep and storage
The bolognese sauce keeps for 4 days in the fridge. Store the zucchini noodles separately and only toss them in the pan briefly when serving, otherwise they turn mushy. The sauce also freezes well (up to 3 months).
Tomato-free variation (for even fewer carbs)
Skip the tomato passata and use 2 tbsp olive oil and 1 tbsp soy sauce instead. The result is a drier, Mediterranean-style mushroom and walnut mix with about 4 g net carbs per serving.
What tips help with keto mushroom and walnut bolognese?
- Pulse the mushrooms and walnuts in short bursts in a food processor, do not puree, the small pieces should stay visible.
- Do not wash the mushrooms before searing, just wipe them with a cloth, moisture prevents browning.
- Only stir the mushroom and walnut mix once it is visibly browned (4 to 5 minutes).
- Toss the zucchini noodles in the pan for just 1 to 2 minutes, they should stay al dente.
- Nutritional yeast works surprisingly well as a parmesan substitute on this bolognese.
Nutrition values
| Nutrient | Per 100 g | Per serving | Keto context |
|---|---|---|---|
| Calories | approx. 92 kcal | approx. 410 kcal | Complete vegan keto meal; energy from walnuts and olive oil. |
| Complete vegan keto meal; energy from walnuts and olive oil. | |||
| Fat | approx. 8 g | approx. 36 g | Main sources: walnuts and olive oil; rich in omega-3 (ALA) and monounsaturated fats. |
| Main sources: walnuts and olive oil; rich in omega-3 (ALA) and monounsaturated fats. | |||
| Net carbs | approx. 1.6 g | approx. 7 g | Low; comes from zucchini, tomato passata and walnuts. |
| Low; comes from zucchini, tomato passata and walnuts. | |||
| Sugar | approx. 1.0 g | approx. 4 g | Natural sugar from tomatoes and zucchini. |
| Natural sugar from tomatoes and zucchini. | |||
| Protein | approx. 2.7 g | approx. 12 g | Plant protein from walnuts and mushrooms. |
| Plant protein from walnuts and mushrooms. | |||
| Salt | approx. 0.2 g | approx. 0.8 g | Low; from seasoning. |
| Low; from seasoning. | |||
Note: Nutrition values are estimated averages per 100 g and per serving and may vary depending on ingredients, brands, portion size, and preparation. They do not replace individual nutrition or medical advice.
FAQ
Can I use other mushrooms instead of white mushrooms?
Yes, king oyster or portobello mushrooms work even better, they have more umami and a meatier texture. The net carbs stay essentially the same.
Does the bolognese work without a spiralizer?
Yes, you can also slice the zucchini into wide ribbons with a vegetable peeler. Alternatively, serve the bolognese over roasted cauliflower.
Are walnuts the best nut as a ground meat substitute?
For bolognese, yes. Walnuts have the right texture and a neutral flavor that absorbs tomato sauce well. Pecans are the next best alternative.
Does the bolognese work as meal prep for the office?
The sauce is ideal for meal prep. Transport the zucchini noodles separately and warm them in the microwave for 1 minute before eating, then add the sauce.