The first step is to steam your tempeh. Steaming is important because it helps the tempeh absorb the marinade and it will make for a better overall texture. You can use your Instant Pot or you can steam it on the stove. Whichever way you choose, first cut your tempeh in half, widthwise.
To use your Instant Pot, add 1 cup of water to the pot and place the trivet on the bottom. Place the tempeh directly on the trivet and lock the lid into place. Make sure the nozzle is in the “sealing” position. Use the manual mode and set the timer for 5 minutes. Use the natural release method when the time is up. If using the stove, add two cups of water to a pot, along with a steamer basket. Place the tempeh in the steamer basket and place a lid on the pot. Steam for 10 minutes.
When the tempeh is steamed, carefully slice both halves, lengthwise, so that you have 4 thinner slabs in total. Set aside for now.
Make the marinade by placing all of the marinade ingredients into a large bowl with a wide bottom, and whisking to combine (orange juice, lime juice, garlic, cumin, oregano, coconut aminos, salt, pepper).
Preheat the oven to 375°F (190°C) and then place the tempeh in the bowl with the marinade and marinate for about 15 minutes, turning over once or twice so all of the tempeh absorbs some marinade.
Place the tempeh on a parchment covered baking sheet and pour the leftover marinade on top. Bake for 15 minutes, take out of the oven, flip over, and bake for an additional 15 minutes.
Allow to cool completely before you store in the fridge.
Sandwich
Toast your English Muffin (or regular bread if using that). Spread some Mustard Dressing on each muffin half (link to recipe in recipe notes) and layer with tempeh, cucumber and sprouts.