Preheat oven to 350°F (175°C). Cut a piece of parchment paper to fit the bottom and up the two long sides of a 5" x 9" loaf or cake pan.
Place all of the Sauce ingredients into a small bowl and whisk until smooth. Set aside for now.
In a small saucepan, combine the water, steel cut oats, Worcestershire sauce and tomato paste. Bring to a boil, turn the heat to low and cover the saucepan with a lid. Simmer over low heat for 15 minutes, stirring occasionally so it doesn’t stick. After 15 minutes, remove the lid and set aside to cool.
Toast the bread, tear into small pieces and place them into your food processor and process until they become soft crumbs. Transfer the crumbs to a large mixing bowl (No need to wash the food processor).
In the empty food processor, place the mushrooms, pinto beans, pecans, onion, ground flax seeds, smoked paprika, garlic granules, salt and pepper and process until everything is chopped into small pieces but not pureed (10 to 20 seconds). Stop intermittently during this time and scrape down the sides of the food processor and then continue processing.
Add this mixture to the large mixing bowl that has the breadcrumbs, along with the steel cut oats mixture and the nondairy milk. Mix everything together until well combined.
Scoop the entire mixture into the lined loaf pan and pack it down with a spoon. Evenly spread the Sauce that you made earlier over the entire loaf and bake for 65 minutes.
Allow to cool for 15 minutes. When cool enough to handle, lift the meatloaf out of the pan by the parchment paper and set onto a cutting board. Allow to cool for 10 additional minutes and then cut the meatloaf into slices.
Meatloaf will firm up after it cools.