Easy Crispy Mushroom Tempura (Vegan / Gluten-Free)

Name: Easy Crispy Mushroom Tempura (Vegan / Gluten-Free)
Prep time: 15 min
Cook time: 5 min
Total time: 20 min
Cuisine: Asian
Ingredients: 2 cups sliced mushrooms ((oyster, king oyster, cremini, etc)); 1/2 cup white rice flour; 1/4 cup cold sparkling water (or more, depending on the brand rice flour used*); 1/4 tsp salt; a pinch of baking soda; optional: 1 tbsp finely chopped cilantro; 2 cups vegetable oil; 2 tbsp soy sauce; 1 tbsp water; 1 tsp maple syrup; 1 tsp lime juice; 1/2 small chili (finely chopped (optional))