If you haven't roasted your bell peppers yet, simply set your oven to BROIL and cut the 4 sides off of the pepper, discarding the white center and seeds. Arrange the pepper pieces skin-side up in a single layer on a large baking sheet, then place the sheet about 6 inches away from the heat source. Broil until the skins are blackened, about 10 minutes, then remove the pan and place the broiled peppers in a glass dish with an airtight lid. Let the peppers steam in that dish for 20 minutes, until they are cool enough to handle, then gently peel away the black skins. (They should slip off very easily.) Slice the roasted peppers into strip for your sushi bowls.
To prepare the dressing, combine the olive oil, tamari, ginger, garlic, vinegar, maple syrup, and sesame oil, in a blender. Blend until completely smooth and adjust any seasoning to taste. (Keep in mind that it will be salty, but will be diluted over all those veggies.)
To prepare the jicama rice, place the peeled cubes in a food processor bowl fitted with an "S" blade and briefly pulse until a rice-like texture is created.
To assemble the sushi bowls, start with a serving of the jicama rice, then add in the sliced bell peppers, carrots, cucumbers, green onions, sliced avocado, and sesame seeds. Drizzle on the dressing, to taste, and serve immediately.
I recommend storing any leftover ingredients separately in airtight containers in the fridge for best shelf life. These items should last up to a week in the fridge if you don't finish them faster than that.