Bring water to a boil and add 1/2 cup farro all at once. Return to a boil, then reduce heat to medium low and gently simmer for about 20 minutes. Check after 20 minutes, test the farro, if there is a very slight bite or crunch, the farro is done, drain and set aside.
Heat 1 tbsp olive oil in a medium sauté pan, add 1 small shallot chopped and cook for 3-4 minutes, or until the shallots start to soften. Add 1 small garlic clove, grated to the shallots, cook for about a minute, then add 1/4 cup chicken stock or vegetable stock. Add 1 tbsp balsamic vinegar and simmer for 1 to 2 minutes.
Add 1 10 oz bag baby spinach. Season with kosher salt to taste, toss to combine, then cover and simmer for 3 to 4 minutes, or until the spinach has reduced by half in volume.
Add cooked farro, toss to combine and remove to a platter. Drizzle with the dressing, grate the zest of one lemon on the farro mixture. Toss gently to combine. Top with baby plum tomatoes.
