Preheat the oven to 350°F (175°C).
Cook the egg noodles according to package instructions until al dente. Drain and set aside.
In a large skillet, heat olive oil over medium heat. Add the chopped onion and cook for 3-4 minutes until softened.
Add the minced garlic and sliced mushrooms to the skillet. Cook for an additional 5-6 minutes until mushrooms are tender and any liquid has evaporated.
Stir in the thawed peas and cook for 1 minute.
In a large mixing bowl, combine the cooked onion, garlic, mushrooms, peas, flaked tuna, condensed cream of mushroom soup, chicken broth, almond milk, dried thyme, black pepper, and salt. Mix well.
Add the cooked egg noodles to the mixture and gently fold until everything is evenly combined.
Transfer the mixture to a 9×13 inch baking dish and spread evenly.
In a small bowl, mix the breadcrumbs with melted butter until the crumbs are evenly coated.
Sprinkle the breadcrumb mixture evenly over the casserole.
Bake uncovered in the preheated oven for 25-30 minutes, or until the casserole is bubbly and the topping is golden brown.
Remove from the oven and sprinkle fresh chopped parsley on top before serving.