Line a sheet pan with foil and add brussels sprouts and cherry tomatoes to the pan. Toss veggies with oil, salt, garlic powder, thyme and oregano and roast for 10 minutes.
Remove pan from the oven and push veggies to one side. Pack a 1/4 cup measuring cup with the tuna mixture to form 4 patties. Push patties down a bit on the pan and bake for 10 minutes, then flip them and bake for another 10 minutes.
*If you have a nut allergy you can use 2 tablespoons coconut flour instead of almond flour