Rinse all vegetables under cold running water. Trim stems of broccoli and cauliflower; cut into uniform florets about 1 to 1½ inches. Peel carrots if desired and slice on a bias into 1/4-inch pieces so they cook evenly. Trim snap peas. Halve baby zucchini lengthwise. Pat vegetables dry with a clean towel.

Measure and arrange

Arrange vegetables by cooking time: place carrots and cauliflower together (longest), broccoli and zucchini together (medium), and snap peas last (shortest). This will help you add them to the steamer in stages if you prefer mixed textures.

Steaming

Set up steamer

Add 1 cup water to a medium saucepan or pot with a tight-fitting lid. Fit a steamer basket or metal colander above the water so the water does not touch the basket. Bring the water to a brisk simmer over medium-high heat.

Steam vegetables in stages

Add the carrots and cauliflower to the steamer basket first, cover, and steam for 3 minutes. After 3 minutes, add broccoli and zucchini on top, cover and steam for an additional 2 minutes. Finally add the snap peas, cover and steam for 1 to 2 minutes more, until all vegetables are bright, tender-crisp, and easily pierced with the tip of a knife. Total steaming time will be about 6 to 8 minutes depending on the size of the pieces and your desired doneness.

Check doneness and remove

Remove the steamer basket from the pot and immediately transfer the vegetables to a large bowl or shallow dish to stop cooking from residual heat. If you prefer slightly softer veggies, let them rest covered for 1 minute; for crisper texture, transfer immediately.

Seasoning & Serving

While vegetables are steaming or immediately after removing them, drizzle 2 tablespoons of extra-virgin olive oil over the vegetables. If using butter, add 1 tablespoon while vegetables are hot so it melts and coats them.

Add 1 tablespoon fresh lemon juice, 1 teaspoon lemon zest (if using), 3 teaspoons sea salt (adjust to taste) and 1 teaspoon freshly ground black pepper. Toss gently but thoroughly so all pieces are evenly coated. Taste and adjust seasoning—add more salt, pepper, or lemon as desired.

Sprinkle 2 tablespoons chopped fresh parsley or dill and 2 tablespoons toasted sliced almonds or sesame seeds for texture and garnish. Serve immediately while warm.

If preparing ahead, cool vegetables quickly on a shallow tray, refrigerate in an airtight container up to 2 days, and reheat gently in a steamer or briefly in a skillet with a splash of water and a drizzle of oil.