Preparation
1. Melt butter in a large saucepan set over medium-high heat. When bubbly, add onion. Stir often just until onion begins to soften, from 1 to 2 minutes. Add garlic and mushrooms. Sprinkle in salt and ¼ teaspoon (1 mL) thyme. Stir often until mushrooms are golden-tinged, from 3 to 4 minutes. Meanwhile, coarsely chop tomatoes and thinly slice green onions. Set green onions aside. Stir in tomatoes with any juice and seeds and orzo. Then pour in chicken broth.
2. Using a wooden spoon, scrape up and stir in any brown bits from pan bottom into sauce for added flavour. Stir constantly until orzo absorbs most of liquid in pan, about 5 minutes. Add water and stir often until most of liquid is absorbed, from 4 to 5 minutes. Mixture should look a little soupy.
3. Remove from heat and stir in cheese and green onions until cheese has melted, about 1 minute. Taste and stir in remaining ¼ teaspoon (1 mL) thyme, if needed. Ladle risotto into warm soup bowls and serve immediately with a leafy green salad and thick slices of fresh focaccia or pumpernickel.