Line a baking pan with parchment paper.
Top it with the whole cherry tomatoes, two thirds of the sliced onions, a pinch of salt and pepper.
Toss the ingredients together with a teaspoon of olive oil. Roast at 400F for 15 minutes
Sauté the final third of sliced onions in a little oil until soft.
Add a teaspoon of the minced garlic and stir quickly before adding the sliced Swiss chard.
Sauté for a few minutes until the Swiss chard wilts.
After 15 minutes, add the white beans and 2 teaspoons of the minced garlic to the tomatoes and onion and toss well to incorporate.
Pop the baking pan back in the oven for just 3 minutes.