I ordered build-your-own bowls from Cava and Sweetgreen. Both tasted delicious, but the winner didn't charge for as many add-ons.

I attended a restaurant conference where I gorged on samples of vegan chicken, sushi, and brownies; I had a teriyaki burger and McPops at McDonald's Global Restaurant; I tried the massive portions at the Cheesecake Factory; and I sampled fine dining at a Michelin-starred restaurant.

A number of them were designed to be ordered as is, which started at $12.95, but you could also build your own in a walk-the-line format from $9.95. Mine ended up costing far more than this, though.

I started with a wild rice and herbed quinoa base — I liked that I could go 50/50 with them. There was a good choice of cold toppings, including different cheeses, nori sesame seasoning, spicy broccoli, crispy rice, and almonds.

The prices varied considerably at the restaurant I visited: it was $6.25 for steak, $5.95 for salmon, $2.10 for avocado, and $1.50 for blue cheese, goat's cheese, and shaved Parmesan. Keeping track of how much your meal will cost requires some quick maths.

These included kale, pickled onions, warm portobello mushrooms, roasted tofu, avocado, tomatoes, and breadcrumbs. I had to pay extra for the mushrooms, tofu, and avocado.

I wasn't sure what would go with the odd array of ingredients I'd chosen. Olive oil would have worked but would have been a bit boring. I asked the staff member for recommendations, and they suggested the Green Goddess Ranch.

I'm so glad they did.

I'm a Brit who's rarely eaten ranch — and I didn't know what made the ranch green. Turns out it was cilantro and parsley, two of my least favorite herbs. After a few tastes, I had to throw the tub away.

I thought it tasted delicious, though the mushroom wasn't as flavorsome as I'd expected and it was a shame about the dressing.

Unlike the Sweetgreen I visited, the Cava was crammed full of customers. The restaurant — Chicago's first Cava — had only opened three weeks before, and residents of the Windy City were clearly eager to check out the buzz. It took me an hour to get to the front of the line.

Customized grain bowls, salads, and pitas make up roughly 85% of Cava's orders. Prices for its most basic "curated" bowls start at $12.05, the same as a custom bowl with no paid-for add-ons.

You can get harissa honey chicken, braised lamb, Persian cucumber, spiced feta, and red pepper hummus. Dressings include balsamic date vinaigrette, tahini Caesar, and skhug — a spicy, herby sauce from Yemen.

When I visited, three of the seven items described as "mains" — harissa honey chicken, braised lamb, and spicy lamb meatballs — incurred extra charges. Cava has now added grilled steak to this list, too.

This included vegetable slaw, hummus, and cheese, all of which incur extra charges at Sweetgreen. Falafel, roasted white sweet potato, grilled chicken, and roasted vegetables were free, too.

I went for Cava's SuperGreen mix topped with roasted white sweet potato, falafel, hummus, roasted eggplant dip, black olives, pickled pink onion, cabbage slaw, and garlic dressing. I also added Cava's pita crisps for free. My bowl looked monstrous, but it tasted great.

As I didn't get any of the paid-for extras, I was just charged the base price of $12.05 before tax. With a drink, it came to $17.22, including tax.

I can avoid ingredients I don't like, such as cilantro, parsley, and raw carrot — as well as the embarrassment of having to ask a member of staff if the restaurant could make a set menu item without these ingredients.

Though Sweetgreen offered a cheaper basic bowl — $9.95 versus $12.05 — many more of the toppings incur extra costs. I loved that Cava's falafel and sweet potato didn't cost more. If you made a bowl at Sweetgreen without any of the add-ons, it would be tasty but lacking some oomph.