To make hollandaise, heat large skillet over medium heat. Once hot, add oil and garlic. Sauté for 1 to 2 minutes, or until very light golden brown.
Add flour or arrowroot starch. Whisk to combine. Cook for 1 minute.
Slowly add in almond milk and vegetable broth, whisking to prevent clumps.
Add lemon, tahini (optional), nutritional yeast, salt, pepper, maple syrup or agave nectar, and hot sauce (optional). Whisk to combine and continue cooking over medium heat to thicken.
Transfer mixture to blender (optional, as blending makes it more creamy, but is not vital to the final product) and blend until creamy and smooth. Taste and adjust seasonings as needed. Return to pan over low heat to keep warm.
If the sauce is too thin, scoop out 1⁄2 cup and whisk in an additional 2-3 tsp flour or arrowroot starch. Then whisk back into the sauce and continue cooking over medium-low heat until thickened. Repeat process as needed.
As sauce is cooking, heat a large skillet over medium heat. Once hot, add olive oil and tomato slices and season with a pinch each salt and pepper. Brown for 2 minutes on each side. Set aside.
Remove tomatoes from skillet and add English muffins cut-side down to slightly warm/brown for 2-3 minutes.
To serve, top English muffins with tomato slices, avocado, and a generous portion of hollandaise sauce. Garnish with paprika or parsley for color (optional).