Heat the olive oil in a large sauté pan over medium-high heat. Add the onions and 1/2 t of salt. Cook until the onions begin to soften, about 5 minutes. Then, add the garlic and cook until fragrant, about 30 seconds.
Pour the red wine over the onion mixture and cook down until almost completely evaporated. Add the chard stems, if using, 1/2 - 1 t salt and the mushrooms. Cook until the mushrooms begin to wilt and release their liquid.
Add the tomatoes, and bring to a simmer before adding the greens.
Cook until the sauce starts to thicken. Add the cauliflower rice and heat through. Serve with your choice of protein, herbs, flavored oils and a hearty topping of grated cheese.