Once your poblano chiles are roasted and peeled, using a knife, make a vertical cut from the stem to the tip of the chile.
Fill with your favorite vegan cheese, close the chile, and secure with toothpicks. Set aside.
To make the sauce
Place the tomatoes, garlic, and onion in the blender and process until smooth.
Heat a medium sauce pot to medium heat and add the tomato sauce. Simmer for 7 – 10 minutes or until the sauce begins to thicken. Season with salt and pepper. Set aside.
To make the batter
Combine the flour, chickpea flour, cornstarch, and salt in a large bowl. Pour in soda water gradually and whisk, until the batter reaches the consistency of a thin pancake batter.
Heat three inches of oil in a high sided pan to 360°F. Dip each chile into the batter, letting excess drip off, then place in oil and fry until golden, about 5 minutes on each side.
Remove the chiles and place on a plate lined with paper towels to absorb excess oil.
Serve the chile on top of a plate of the tomato sauce
My favorite vegan cheese for chiles rellenos is Chao cheese, which comes in slices, but I grated it anyway on a box grater. I have also made this with my macadamia nut queso fresco, which doesn’t melt, but behaves very much like a fresh farmer’s cheese. Both cheeses gave good results.If you want the batter to be yellowish like traditional chiles rellenos you can add 1/4 tsp. of turmeric to the batter.