Prep
Preheat oven to 375°F (190°C).
Line a loaf pan with parchment paper.
Sauté the Vegetables
Heat olive oil in a skillet over medium heat.
Add onion and cook for 3–4 minutes until softened.
Add garlic and mushrooms.
Cook until mushrooms release moisture and mixture softens (about 5–7 minutes).
Remove from heat and let cool slightly.
Mix the Roast
In a large bowl, lightly mash lentils with a fork (leave some texture).
Add sautéed vegetables, oats, nuts, tomato paste, soy sauce, thyme, rosemary, smoked paprika, salt, and pepper.
Mix until well combined.
If mixture feels dry, add 1–2 tablespoons vegetable broth.
Texture should be thick and moldable.
Shape and Bake
Press mixture firmly into prepared loaf pan.
Smooth the top evenly.
Bake for 35–45 minutes, until firm and lightly browned.
Optional Glaze
During the last 10 minutes of baking, brush top with ketchup-maple mixture for a glossy finish.
Rest and Slice
Let roast rest for 10–15 minutes before slicing to help it firm up.