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 2 tablespoons olive oil over medium heat. Add diced onion and cook for 3-4 minutes until softened.
Add minced garlic and sliced mushrooms to the skillet. Cook for 5-6 minutes until mushrooms are tender and browned.
Sprinkle the flour over the mushroom mixture and stir well to coat. Cook for 1-2 minutes to remove the raw flour taste.
Gradually whisk in the chicken broth and almond milk, stirring constantly to avoid lumps.
Add dried thyme, black pepper, and salt. Simmer the sauce for 5-7 minutes until it thickens.
Remove the skillet from heat and stir in the drained tuna and thawed peas.
In a large mixing bowl, combine the cooked noodles and the tuna mushroom sauce. Mix well.
Transfer the mixture to a greased 9×13 inch casserole dish.
In a small bowl, toss the breadcrumbs with 2 tablespoons olive oil until evenly coated.
Sprinkle the breadcrumb mixture evenly over the casserole.
Bake in the preheated oven for 20 minutes or until the top is golden brown and the casserole is bubbly.
Remove from oven and let it rest for 5 minutes before serving.