Easy oven-roasted vegetables (keto & low-carb) turn a tray of peppers, zucchini, broccoli, cauliflower, and mushrooms into caramelized, colorful perfection. A seasoned avocado oil blend with basil, oregano, and rosemary coats every piece before a hot oven does the rest. It is the versatile meal-prep side that lifts any dinner, at 5.2 g net carbs per serving.
There’s something magical about a tray of colorful vegetables roasting in the oven. The aroma that fills your kitchen, the vibrant colors deepening, and the edges caramelizing to perfection—it’s simple, wholesome cooking at its best! This recipe is my go-to for weekly meal prep because it’s incredibly versatile. Toss these roasted veggies with your favorite protein for a quick dinner, add them to a breakfast scramble with eggs, or pile them into a hearty lunch bowl. They are a delicious and effortless way to add a boost of flavor and nutrition to any meal.
Ingredients
• 1 medium red bell pepper, seeded and cut into large chunks
• 1 medium orange bell pepper, seeded and cut into large chunks
• 1 medium yellow bell pepper, seeded and cut into large chunks
• 1 medium zucchini, sliced and cut into half moons
• 10 ounces / 285g (10.1 oz) broccoli florets
• 10 ounces / 285g (10.1 oz) cauliflower florets
• 8 ounces / 225g (7.9 oz) cremini mushrooms, halved or quartered
• ½ small red onion, cut into large chunks
• ¼ cup / 60ml (2 fl oz) avocado oil
• 1½ teaspoons sea salt
• 1½ teaspoons garlic powder
• 1 teaspoon (5 ml / 0.2 fl oz) onion powder
• 1 teaspoon (5 ml / 0.2 fl oz) dried basil
• 1 teaspoon (5 ml / 0.2 fl oz) dried oregano
• 1 teaspoon (5 ml / 0.2 fl oz) dried rosemary
• ½ teaspoon dried thyme
• ½ teaspoon ground black pepper
Instructions
1. DIRECTIONS
2. Preheat the oven to 425°F / 220°C.
3. Spread the vegetables in a single, even layer across a large rimmed baking sheet. If needed, use two baking sheets to avoid overcrowding, which can cause the vegetables to steam instead of roast.
4. In a small mixing bowl, whisk together the avocado oil, sea salt, garlic powder, onion powder, basil, oregano, rosemary, thyme, and black pepper.
5. Drizzle the seasoned oil mixture evenly over the vegetables and toss thoroughly to ensure every piece is well-coated.
6. Roast for 20 minutes, then gently toss the vegetables. Return to the oven and roast for an additional 15 minutes, or until the vegetables are tender and have developed caramelized, slightly charred edges.
Nutritional Information
• PER SERVING
• CALORIES: 89
• FAT: 5.8g
• PROTEIN: 2.8g
• TOTAL CARBS: 7.9g (0.28 oz)
• FIBER: 2.7g
• NET CARBS: 5.2g (0.18 oz)
Pro Tips
• For a shortcut, replace the oil and dried herbs with ¼ cup of a quality pre-made Garlic and Herb–Infused Olive Oil.
• Cut vegetables into uniform, bite-sized pieces to promote even cooking. Harder vegetables like cauliflower can be cut slightly smaller than softer ones like zucchini and bell peppers.
• Don’t overcrowd the pan! Giving the vegetables space allows hot air to circulate, which is essential for achieving that delicious browning and caramelization.
• Store leftovers in an airtight container in the refrigerator for up to 4 days. Reheat in the oven or an air fryer to restore some of their crispiness.
FAQ
Q: What is the best temperature for roasting vegetables
A: For perfectly tender and caramelized vegetables, preheat your oven to 425°F (220°C). This high heat helps the edges get brown and crispy.
Q: How do I prevent my roasted vegetables from getting soggy
A: The key to avoiding soggy vegetables is to not overcrowd the pan. Spread them in a single, even layer on your baking sheet, using two sheets if needed. This gives the vegetables space to roast rather than steam.
Q: How long do leftover roasted vegetables last
A: You can store leftover roasted vegetables in an airtight container in the refrigerator for up to 4 days. Reheat them in the oven or an air fryer to restore some of their original crispiness.
Q: Can I use different vegetables in this recipe
A: Yes, this recipe is incredibly versatile. You can substitute with other vegetables you have on hand. For even cooking, try to cut harder vegetables like carrots or potatoes slightly smaller than softer ones like zucchini.
Pro Tips
- Spread the vegetables in a single layer and use two baking sheets if needed. Crowding traps steam, and you lose the caramelized, slightly charred edges that make this dish.
- Cut everything into uniform bite-sized pieces, and cut harder vegetables like cauliflower slightly smaller than soft ones like zucchini so they finish at the same time.
- Roast for 20 minutes, toss, then give them another 15 minutes — the mid-roast toss is what gets every side golden instead of just the tops.
- For a shortcut, replace the oil and dried herbs with ¼ cup of a quality garlic and herb-infused olive oil.
- Leftovers keep in an airtight container in the refrigerator for up to 4 days; reheat in the oven or an air fryer to restore their crispiness.
Frequently Asked Questions
Can I meal prep these roasted vegetables?
Yes, they are built for it. Store in an airtight container in the fridge for up to 4 days and rewarm in the oven or air fryer to bring the edges back.
Why are my roasted vegetables soggy?
Almost always overcrowding. Give the pieces space across the pan (use two sheets if needed) so hot air circulates and browns them instead of steaming.
Is this vegetable mix keto-friendly?
Yes. Each of the 6 servings has 7.9 g total carbs and 2.7 g fiber — 5.2 g net carbs — with 5.8 g fat and 89 calories.
Can I swap the vegetables?
Absolutely — the method works for any sturdy vegetables. Just match piece sizes and keep firmer vegetables cut a little smaller so everything roasts evenly.
Recipe card below.
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Easy Oven-Roasted Vegetables (Keto & Low-Carb)
Ingredients
Method
- DIRECTIONS
- Preheat the oven to 425°F / 220°C.
- Spread the vegetables in a single, even layer across a large rimmed baking sheet. If needed, use two baking sheets to avoid overcrowding, which can cause the vegetables to steam instead of roast.
- In a small mixing bowl, whisk together the avocado oil, sea salt, garlic powder, onion powder, basil, oregano, rosemary, thyme, and black pepper.
- Drizzle the seasoned oil mixture evenly over the vegetables and toss thoroughly to ensure every piece is well-coated.
- Roast for 20 minutes, then gently toss the vegetables. Return to the oven and roast for an additional 15 minutes, or until the vegetables are tender and have developed caramelized, slightly charred edges.
- Cut vegetables into uniform, bite-sized pieces to promote even cooking. Harder vegetables like cauliflower can be cut slightly smaller than softer ones like zucchini and bell peppers.
- Don't overcrowd the pan! Giving the vegetables space allows hot air to circulate, which is essential for achieving that delicious browning and caramelization.
