1-First Step: Prep the oven and baking tray Preheat your oven to 425º F. Line a baking tray with parchment paper so cleanup stays simple and the vegetables do not stick. This higher heat is important because it helps the edges brown instead of steaming. If you are making a bigger batch, use two trays so the vegetables can sit in a single layer.

2-Second Step: Cut and arrange the first vegetables Place the quartered new potatoes, cauliflower florets, and sliced leeks on the tray in a single layer. Try not to pile them on top of each other. Crowding the pan traps moisture, and that makes the vegetables softer rather than nicely roasted. A little space between pieces helps them caramelize better.

3-Third Step: Season and roast the first round Drizzle the vegetables with 1 to 2 tablespoons of avocado oil or olive oil. Then season them with sea salt and black pepper to taste. Toss gently so every piece gets a light coating. Roast for 25 minutes, stirring once if you want more even browning. During this first stage, the potatoes begin to soften and the cauliflower starts turning golden.

4-Fourth Step: Add the asparagus and lemon After 25 minutes, carefully remove the tray from the oven. Add the asparagus pieces and toss them with the other vegetables so they pick up some of the oil and seasoning already on the pan. Lay the thin lemon slices on top. The lemon does more than add fragrance. It releases a sweet, fresh flavor as it roasts, which brightens the whole dish.

5-Final Step: Finish roasting and serve hot Return the tray to the oven and roast for another 10 minutes. The asparagus should look bright green and tender, while the potatoes and cauliflower should be browned at the edges and soft enough to pierce with a fork. If you are adding herbs, sprinkle them on just before serving so they stay fresh and colorful. Serve the vegetables hot as a side dish or pile them into a bowl as a simple vegetarian meal.